tag:blogger.com,1999:blog-17184216954174416692023-11-16T02:20:41.061-08:00Mesozoic ArchivesYou're about to learn about the past in whole new ways.Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.comBlogger49125tag:blogger.com,1999:blog-1718421695417441669.post-52961125011211517352015-07-10T15:34:00.000-07:002015-07-10T15:34:08.937-07:00Goodbye Mesozoic Archives, Hello NMPDN!For those of you still here, I'd like to inform you that Mesozoic Archives is, as of now, defunct and null void. I had a great early start at blogging here, but now, after a long leave of absence, I realize that many of my earlier writings on this blog are quite amateur, and I'd like to try a different format and environment for writing.<br /><br />As such, I've decided that I shall be making a move to a separate blogging location. My new blog, titled <a href="http://nmpdn.blogspot.com/">Notions of a Most Peculiar Dinosaur Nerd</a>, will be a blog focusing on Paleontology, but also cover various topics of Biology, Science Fiction, Worldbuilding, Art, and many other topics I (and I hope others) find interesting.<br /><br />It's sad to see the old place go, but I hope you’ve learnt from writings and enjoyed the place. Thank you for your support, and wish you all to join me at my new location. Cheers, and see you there! :)Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-26487551329507347032014-11-05T22:56:00.000-08:002014-11-06T09:03:17.058-08:00My Opinions on the NOVA Spinosaurus Documentary.<div class="separator" style="clear: both; text-align: center;">
<a href="http://www-tc.pbs.org/wgbh/nova/assets/img/posters/bigger-than-t-rex-vi.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://www-tc.pbs.org/wgbh/nova/assets/img/posters/bigger-than-t-rex-vi.jpg" height="180" width="320" /></a></div>
So, I just finished watching the new <i>Spinosaurus </i>documentary on PBS titled "Bigger than <i>T. rex</i>". I decided to post a review of the documentary on Facebook from the notes I took. It ended up getting so long that it could take up a blog post. As such, here it is:<br />
<br />
<div class="_5pbx userContent" data-ft="{"tn":"K"}">
<i>My thoughts on the NOVA
Spinosaurus documentary:</i><br />
<br />
<i> -Saw an ad for the museum I work at prior to the start of the show. Tis a good sign.<br />
-Still don't like the title. People need to be more creative with their
titles. Why does everything need to be compared to T. rex for Pete sake?<br /> -Typical promising NOVA opening. Draws you in and gets you in the mood quickly.<br /> -CAMELS!!! I love Camels. <br /> -Peter Dodson's comparison of Spinosaurus to Nessie immediately brought this to mind:</i> <i><b><a href="http://thewoodparable.deviantart.com/art/Nessie-a-derived-spinosaurid-482581711" rel="nofollow" target="_blank">http://thewoodparable.deviantart.com/art/Nessie-a-derived-spinosaurid-482581711</a></b><br />
-They say something about flesh-eating Mesozoic birds being found in
the Sahara. If somebody knows about this and cares to explain it, please
do, because I have no idea what they're talking about...<br /> -The typical NOVA animations and reenactment scenes really fit the mood. Just my personal opinion.<br />
-I don't think I really understood exactly how crazy the re-tracking of
this specific fossil hunter was until I watched this. Nizar really did
have some awesome luck going for him.<br /> -Camel playing with a coke
bottle. I can't tell if this is brilliant product placement, or they
were short 5 seconds of footage and decided to give a camel a coke
bottle and record what happens to fill it up. Either way, I approve.<br />
-I just noticed this, but Spinosaurus as a species has been referred to
as a "he" multiple times in the documentary so far. Why? Were there no
female Spinosaurus or something? Is that why they're extinct?<br /> -Just wanted everyone to know, I called this predators in Kem Kem ate fish thing first:</i> <i><b><a href="https://www.youtube.com/watch?v=JuYo5-YuAoM" rel="nofollow" target="_blank">https://www.youtube.com/watch?v=JuYo5-YuAoM</a></b><br /> -Me: Please explain your methods!<br /> *Never explains methods.*<br /> Me: Dammit...<br />
-Stop saying birds are dinosaur's "closest living relatives". Just say
they ARE dinosaurs! It makes us museum interpreters' lives so much
easier.<br /> -Bubba is the most calm Alligator I've ever seen. I want to hug him. <br /> -I still don't think everyone agrees the sail looked like that, but, whatever...<br />
-Sereno says briefly something about Spinosaurus having the most
massive forearms of any dinosaur. Er, Deinocheirus? Therizinosaurus?
Heck, go outside of theropods and point out Brachiosaurus! Why do they
get no love?<br /> -Again, not everyone agrees with the quadrupedal thing, but, whatever...<br />
-The animated life-model doesn't look anything like the mount. I mean,
it's got long legs, short forelimbs, etc. Doesn't look anything like
what Ibrahim et. al. have stated. <br />
-The feeding animation at the end was a disappointment. I wanted to see
a Spinosaurus dive and swim after fish. Instead you saw it swim for 2
seconds, then it skipped a scene and went to heron-fishing... That's not
what I signed up for! <br />
-"Spinosaurus makes sense." Tell that to all the scientists who are
still scratching their heads while waiting for the monograph!<br /> -Ok, I
get that Spinosaurus has a lot of history behind it, and this discovery
is certainly a major step in our understanding of it, but they give off
this vibe at the end like that this is the end of Spinosaurus' journey
and we know everything we can know. I'm sorry, but no. There's certainly
a lot more to learn from this, and this is going to be talked about and
reviewed over for years to come. Don't tell us this is all over when
we're still waiting for a proper description of these remains!</i><br />
<br />
<i>
Anyways, all in all, a decent watch. It didn't teach me anything I
didn't already know, but I recommend everyone watch it at least once for
typical NOVA documentary goodness. Still, I would've liked to see more
Spinosaurus though. Throughout the whole thing I was getting a Godzilla
2014 vibe of wanting to see more of the actual star through computer
animation, but we only really got to see it in full during the last
10-ish minutes (probably less). Plus, when we finally got to the actual
fishing behavior, it was incredibly dull and disappointing. Eh, at least
it was 100x better than Monster's Resurrected.</i><br />
<br />
<i> Now, if you
excuse me, I'm going to be waiting quietly in the corner for the
Spinosaurus monograph we've been promised. Cheers! </i></div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com2tag:blogger.com,1999:blog-1718421695417441669.post-10704817388321196162014-10-04T21:51:00.003-07:002014-10-07T23:26:51.725-07:00Short legs are in?<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKge2ijm1J-P_hTKuYcNF3SPaLDJwgvbmAvirpKsG-ql-YLVn2APakMW24J8lVtEUHd3k_2LW9CZcUEDvwwR2R10kQNsjioRaKbQORvW6OYwFp8-Xgjg-CFUnqOpz8aOk-mUoIA60H-iAv/s1600/10700296_672043386195782_6611084596311018541_o.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKge2ijm1J-P_hTKuYcNF3SPaLDJwgvbmAvirpKsG-ql-YLVn2APakMW24J8lVtEUHd3k_2LW9CZcUEDvwwR2R10kQNsjioRaKbQORvW6OYwFp8-Xgjg-CFUnqOpz8aOk-mUoIA60H-iAv/s1600/10700296_672043386195782_6611084596311018541_o.jpg" height="290" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i>Spinosaurus aegypticus</i> discusses with a certain individual of <i>Homo sapiens</i> about movie star traits.</td><td class="tr-caption" style="text-align: center;"><br /></td><td class="tr-caption" style="text-align: center;"><br /></td></tr>
</tbody></table>
So, everyone that's been keeping up with the Spinosaurus stuff these past few weeks have probably seen <a href="http://markwitton-com.blogspot.com/2014/09/the-spinosaurus-hindlimb-controversy.html">this post by Mark Witton</a> by now. In it, Ibrahim and co. consulted with Mark and checked over the proportions and scaling in his model, <a href="http://markwitton-com.blogspot.co.uk/2014/09/the-spinosaurus-reboot-sailing-in.html">which Mark checked a few days prior</a> and found similar results to <a href="http://www.skeletaldrawing.com/home/theres-something-fishy-about-spinosaurus9112014">Scott Hartman's own numbers</a>. They found out that the big scaling gap between their model and Scott and Witton's models was actually due to some scaling issues in<i> </i>the latter two's models with vertebrae D8, and when compensating for this, the short limbs become perfectly apparent. Scott later confirmed to me on Facebook that he was able to replicate their corrections, and that he was going to be talking more with the authors about things.<br />
<br />
<div style="text-align: center;">
So, what does this mean?</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<i><b>Spinosaurus' comically short legs are real.</b></i></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
And my thoughts?</div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: center;">
<b>...AWESOME!!!</b></div>
<br />
Seriously though, I was skeptical about the rear legs being that short due to all the questions and criticism being brought up about it. After all, extraordinary claims require extraordinary evidence, and when the evidence didn't seem to hold up, people should show skepticism to the idea proposed. That's what being a scientist is all about. This time however, Ibrahim and co. managed to shine through and show that their short-legged model held up to the intense scrutiny. Really great job on their part answering our questions, and their openness and willingness to talk and discuss has been a great asset to solving these problems.<br />
<br />
Now, however, we should get onto the important bits about what the new legs actually mean. <i>Spinosaurus </i>being Mr. Shortstuff hasn't been too popular with people that I know (particularly a friend of mine who's a big Spino Fan), as well as many typical members "JP3 Fanboy" community on the internet. I, however, fully embrace this new model for <i>Spinosaurus</i>, since unlike those people, I don't care what <i>Spinosaurus </i>as an animal<i> </i>looked like. However I do care about <i>why </i>it looks that way, and that's where the biological questions of this new model come in.<br />
<br />
So, how's a short-legged <i>Spinosaurus </i>going to function? The biggest question I and many people have is how it's going to be moving around on land easily. Ibrahim and co.'s proposed quadrupedal model still doesn't hold up in my opinion (for the reasons brought up on <a href="http://qilong.wordpress.com/2014/09/12/the-outlaw-spino-saurus/">Headden's post</a> as well as elsewhere), but then how is it going to be moving around? A few people have brought up some ideas on Facebook and elsewhere, but the Pangolin method of locomotion proposed by Darren Naish sounds plausible. By hunching over and sticking its tail out strait back, it might've been able to waddle around on land like a pangolin with some success. Perhaps also like a pangolin, it could've used its forelimbs to right itself occasionally while walking on rough terrain, but nothing like constant quadrupedal movement.<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.youtube.com/embed/gz4HXyxcess?feature=player_embedded' frameborder='0'></iframe></div>
<div style="text-align: center;">
<i><span style="font-size: x-small;">Pangolin waddling along... Waddle, waddle...</span></i></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: left;">
Moreover, as many people who've read about this already know, <a href="http://archosaurmusings.wordpress.com/2012/08/28/variation-of-tail-length-in-dinosaurs/">tail length in dinosaurs is highly varied</a>, even on the individual level, and
it's likely that many dinosaurs may have under-sized and/or over-sized
tail proportions. <i>Spinosaurus' </i>tail could've been a good 20% longer than Ibrahim and co. proposed for all we know, if not more.
It is also important to remember that dinosaurs, and particularly
theropods, had massive, thick tails which would've been effective
counterbalances. With the apparent presence of an extremely
well-developed caudofemoralis muscle suggested by Ibrahim and co. for paddling, the tail might be extremely bulky, and this could help balance out their <i>Spinosaurus </i>even more while walking.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Another interesting method of locomotion that was mentioned online a few times here-and-there was the possibility of a therizinosaur-like or cormorant-like walking. That is, with a near-vertical back. This I thought was an interesting idea for the terrestrial locomotion of this animal. Normal theropods are already capable of upright movement for short periods, and considering that we think Spinosaurus wasn't spending much time on land to begin with, this could be a possible form of movement.</div>
<div style="text-align: left;">
<br /></div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ2KpdJJl3FBz55q6VXWviFhyphenhyphen1_EKKZh68E_NNnFwo5v2HTaOflbzIBiOAWQa2_CNmZzGFiOY5x-_b06hp-aDZQkjrNyHTp0piEuc5YBeF4D12ii0C_MKx7-BrHvOhKJU2SIPMC9N13Cj5/s1600/behold_the_vintagesaur__by_yoult-d7zj8jf.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ2KpdJJl3FBz55q6VXWviFhyphenhyphen1_EKKZh68E_NNnFwo5v2HTaOflbzIBiOAWQa2_CNmZzGFiOY5x-_b06hp-aDZQkjrNyHTp0piEuc5YBeF4D12ii0C_MKx7-BrHvOhKJU2SIPMC9N13Cj5/s1600/behold_the_vintagesaur__by_yoult-d7zj8jf.jpg" height="416" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><span style="font-family: inherit;">Behold the <b>Crococormorant</b>! Art by <a href="http://yoult.deviantart.com/"><b>yoult</b> of Deviantart</a>, and name proposed by <span class="tt-w"><span class="username-with-symbol u"><b><a class="u regular username" href="http://ornithischophilia.deviantart.com/">ornithischophilia</a></b>.</span></span></span></span></td></tr>
</tbody></table>
<div style="text-align: left;">
The posture also brings back images and ideas of retrotheropods from the early and mid-1900s. In fact, wait... Possible upright posture, short legs, strong arms, aquatic habits, the largest theropod, tall extensions on the back.......is <i>Spinosaurus </i>a real-life Godzilla?</div>
<div style="text-align: left;">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div style="text-align: left;">
I'll leave you all with a third and possibly my favorite proposed method of locomotion for <i>Spinosaurus</i>. Stay sharp everyone! Cheers!<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjCAU-lzxa5lhnr5hzbWybkhyphenhyphen0k2gUfdn2AO8U1RqzHZUZ86eGvayLzP1HKxZbdTNOuZectOeoplO6EnkEBSRbsq9ov5VuSLr3ra2xBbvi1FKllmh_44rRDZkICGjNiqjZxnQkcbvtm_F5/s1600/nyansaurus_aegyptiacus_by_osmatar-d81ah7c.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjCAU-lzxa5lhnr5hzbWybkhyphenhyphen0k2gUfdn2AO8U1RqzHZUZ86eGvayLzP1HKxZbdTNOuZectOeoplO6EnkEBSRbsq9ov5VuSLr3ra2xBbvi1FKllmh_44rRDZkICGjNiqjZxnQkcbvtm_F5/s1600/nyansaurus_aegyptiacus_by_osmatar-d81ah7c.jpg" height="417" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Obviously this method of locomotion proposed by <b><a href="http://osmatar.deviantart.com/">Osmatar</a></b> perfectly explains all of the bizarre proportions to the new <i>Spinosaurus</i> </td><td class="tr-caption" style="text-align: center;"><br /></td></tr>
</tbody></table>
</div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com9tag:blogger.com,1999:blog-1718421695417441669.post-50678123343833698232014-09-14T22:44:00.000-07:002014-09-15T13:03:06.451-07:00Spinosaurus is back! <span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt;">So,
if you’re a paleo-nerd like me, you’ve probably read all about the new <i style="mso-bidi-font-style: normal;">Spinosaurus</i> material announced by </span><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Nizar Ibrahim and Paul C. Sereno. If you’re also like me,
you were probably way too ecstatic about the new material announcement to remember
that the same date it was announced also happened to be the 13<sup>th</sup>
Anniversary of World Trade Center Bombings. Looking back on it today, I’m seriously
disappointed in myself that I forgot all about it and spent nearly the whole
day running around like a giddy toddler on a sugar high about these remains. At
the same time though, everybody else that I knew didn’t speak much about the anniversary
either, even on Facebook posts, but I guess that shows that we’re
all moving forward as a society.</span></span><br />
<div style="border-image: none;">
<span style="font-family: Times,"Times New Roman",serif;"><br /></span></div>
<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Anyway, back to the topic. If you’re
part of the 1% who have not kept up with the Spino News, here’s what’s going on.
On September 11th in <u>Science</u>, Nizar Ibrahim and Paul Sereno published their
long-anticipated paper on <i style="mso-bidi-font-style: normal;">Spinosaurus</i>
material recovered from Morocco and other parts of the Sahara, and the material
doesn’t just conclude that <i style="mso-bidi-font-style: normal;">Spinosaurus</i>
was the longest theropod dinosaur, but it also reveals it has anatomy which was, well, bizarre:</span></span><br />
<span style="font-family: Times,"Times New Roman",serif;"><br /></span>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><span style="font-family: Times,"Times New Roman",serif;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizT1jbnl2BTglc0bQdBdSMubTZz0ffhNrW1XC47aweT5cFZIC4clU9YiU8TjJgeT3Xi-lnazO2VDVWtho8kLLmkyi9sercYN8vDYdlLHdonUnvXxe5LdihEwn0lab_GYmDz_jdkOMDiQip/s1600/12dino-1-master1050.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizT1jbnl2BTglc0bQdBdSMubTZz0ffhNrW1XC47aweT5cFZIC4clU9YiU8TjJgeT3Xi-lnazO2VDVWtho8kLLmkyi9sercYN8vDYdlLHdonUnvXxe5LdihEwn0lab_GYmDz_jdkOMDiQip/s1600/12dino-1-master1050.jpg" height="201" width="640" /></a></span></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Times,"Times New Roman",serif;">OMG! What have they done to you Spiny!?</span></td></tr>
</tbody></table>
<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">After the initial shock of the new
artistic restoration and all the reports in the media, I quickly
hunted down the paper and started reading. The new remains show that <i style="mso-bidi-font-style: normal;">Spinosaurus</i> wasn’t only a fish-eating,
aquatic-dinosaur like I have talked about previously, but that it had really
weird anatomy to show for it: things like a more elongate vertebral column, a
more flexible tail, longer and more-developed arms (even more so than other spinosaurids),
and most shocking of all, the downright shortness of the hind legs and
quadrupedal movement of the animal. This was quite interesting, to say the
least, because not only did it challenge a lot of things we thought we know
about <i style="mso-bidi-font-style: normal;">Spinosaurus</i>, but it changed a
lot about what we thought we knew about theropod dinosaurs in general. Let’s
look over this one-by-one: starting with the very short-legged elephant in the
room…</span></span><br />
<span style="font-family: Times,"Times New Roman",serif;"><br /></span>
<br />
<div align="center" style="margin: 0in 0in 10pt; text-align: center;">
<span style="font-family: Times,"Times New Roman",serif;"><b style="mso-bidi-font-weight: normal;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">“No T.rex, please don’t take my fish
and try to make me reach for it…”</span></b></span></div>
<div align="center" style="margin: 0in 0in 10pt; text-align: center;">
<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 8pt; mso-fareast-font-family: "Times New Roman";">- Probably no <i style="mso-bidi-font-style: normal;">Spinosaurus </i></span><i><span style="font-size: 8pt; mso-bidi-font-weight: bold;">aegyptiacus</span></i><span style="font-size: 8pt; mso-bidi-font-style: italic; mso-bidi-font-weight: bold;"> ever. I mean seriously, Spino and T.rex never met. I'm sure all the bullying came from the <i>Carcharodontosaurus</i>.</span></span></div>
<div style="margin: 0in 0in 10pt;">
<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt;">I
do find it interesting that spinosaurids have been suggested as quadrupeds so
many times in literature. There have been mentions of <i style="mso-bidi-font-style: normal;">Spinosaurus</i> as a quadruped since (I believe) the 70s, and the
discovery of <i style="mso-bidi-font-style: normal;">Baryonyx </i>further
promoted this idea with its incredibly robust forearms. Furthermore, the idea
of a quadrupedal theropod isn’t <i style="mso-bidi-font-style: normal;">impossible</i>.
Quadrupedal locomotion evolved at least four other times in the dinosauria all
independently, and even living avian dinosaurs occasionally use their wings to
right themselves, climb, and perform other strange 4-limbed methods of locomotion.
If anything it''s kind of weird that this group of dinosaurs never seemed to evolve
even one semi-quadrupedal member. So is <i style="mso-bidi-font-style: normal;">Spinosaurus</i>
the first? I wouldn’t count on it.</span></span></div>
<span style="font-family: Times,"Times New Roman",serif;"><br /></span>
<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt;">The
proposed evidence that </span><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Ibrahim and Sereno present in the
paper is not very convincing. The primary evidence that they propose is the shortness
of the hindlimbs, which are positively tiny in the reconstructions. This
apparently shifts <i style="mso-bidi-font-style: normal;">Spinosaurus’</i> center
of mass forwards towards the front, thus making it incapable of proper
terrestrial movement. They also point to things such as the strange forelimbs
which have processes which correspond to powerful flexion and extension muscles.
(</span><a href="http://qilong.wordpress.com/2014/09/12/the-outlaw-spino-saurus/"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";"><span style="color: blue;">See Jaime Headden’s post to understand why this still
doesn’t work</span></span></a>.<span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">) This is such a weird arrangement
that many have suggested that the new specimen might be a chimera of two separate
individuals (maybe even of different species) which were stuck together. <a href="http://theropoda.blogspot.com/2014/09/spinosaurus-revolution-episodio-ii-ode.html?spref=tw"><span style="color: blue;">Cau
pointed out earlier today why a chimeric origin is very unlikely</span></a>, but it
doesn’t matter, as this limb shortness might all be untrue anyways.</span></span><br />
<span style="font-family: Times,"Times New Roman",serif;"><br /></span>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Times,"Times New Roman",serif;"><i>Spiny! You're, well, still kinda short...</i></span></td></tr>
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<span style="font-family: Times,"Times New Roman",serif;"><a href="http://www.skeletaldrawing.com/home/theres-something-fishy-about-spinosaurus9112014"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";"><span style="color: blue;">Scott Hartman was quick to point out on his blog</span></span></a><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";"> that the skeletal given doesn’t appear to match the
measurements provided by the authors in their own paper. When corrected, <i style="mso-bidi-font-style: normal;">Spinosaurus</i> gets a bit taller than
before (though he still stays quite short), the center of mass moves back
towards the legs, and the arms are no longer touching the ground. This simple
change completely challenges a large number of the biological suggestions in
the paper, and seems to move <i style="mso-bidi-font-style: normal;">Spinosaurus</i>
back into bipedal territory. This also further convinces me that we should make
a better effort so that discoveries like this are properly published, checked
over, and peer-reviewed <b style="mso-bidi-font-weight: normal;">BEFORE</b> major
broadcasting stations latch onto them and turn them into major money-making
exhibits and documentaries. (Predator X and <i style="mso-bidi-font-style: normal;">Darwinius</i>
anyone?)</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">(Interestingly, the CGI <i style="mso-bidi-font-style: normal;">Spinosaurus</i> being used in the Nova
documentary coming out next month looks like it has its leg proportions
corrected. Although it still does the knuckle-walking thing…)</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Despite this, the morphology of the
arms and legs are still of great interest to me from a biological point of
view. The large caudophemoralis muscle, the proportions of the femur and tibia,
the flat and long digits and claws, the forward-facing hallux, and possible
webbed feet all really suggest an aquatic lifestyle for this animal. What
really seems to cement the idea, however, is the density of the long bones. The
hind limbs are not hollow, are 40% more solid than other theropods, and incredibly
dense. This is seen in aquatic animals to act as ballast and sink into the
water easier while swimming. For a representation of this, go to 37:40 in the
video below for similar limb density in the modern hippo.</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">The forelimbs are also interesting
in that they differ from other spinosaurids in the length of the hands, and
their seemingly better-developed processes for forelimb muscles. Ibrahim and
Sereno suggest that these longer hands would be better at ripping and
dispatching of aquatic prey, but a few people online have also suggested to me
that these adaptations are what you would see in a quadrupedal animal (they’re
not, for the reasons listed above). What I wonder is, if the well-developed
musculature of the forelimbs and seemingly longer digits correspond at all
with paddling. The powerful flexion and extension muscles could be better used for
pushing it along underwater, perhaps while traversing mangroves and river
bottoms in tandem with the hind legs, and the longer digits, like the hind limbs,
may have been webbed to assist in underwater movement.</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">What’s also weird in my opinion is
the vertebral column. It’s pretty long, and in fact gives <i style="mso-bidi-font-style: normal;">Spinosaurus</i> a swan-like neck and dachshund-like body. It is
actually kind of similar to the distantly related theropod <i style="mso-bidi-font-style: normal;">Majungasaurus</i>, who interestingly also has an elongated body, short
hind limbs, and was suggested in passing a few times to be aquatic (Does this
mean anything scientists?). However <i style="mso-bidi-font-style: normal;">Spinosaurus</i>
has it even stranger, with the tail being highly flexible. The authors actually
draw similarities with the tails of bony fish, and suggest that the tail was
used for propulsion via undulations.</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Er, wait… So is <i style="mso-bidi-font-style: normal;">Spinosaurus</i> a foot-propelled paddler, or did it use tail-powered undulations
to move about? Normally animals only do one or the other, not both, and for
good reason. Undulating the body around can mess up the pace of the legs (and
vice versa), and provides no extra acceleration. This is why not many animals
alive today use both methods while swimming. I think that a better explanation
for the anatomy and swimming locomotion should be provided. I propose that most
of its anatomy points to <i style="mso-bidi-font-style: normal;">Spinosaurus</i> being
a foot-propelled paddler, with the flexible tail evolving as a rudder to help
this giant turn its massive body while traversing underwater environments. We
don’t need two swimming methods happening simultaneously when one is good
enough and makes more sense.</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">And then there’s the sail
reconstruction, which I’m also skeptical about. Many recent sail reconstructions
have the long spinuous processes continuing gradually along the spine and down
the tail, but this reconstruction goes back to the early reconstructions seen
throughout the 20<sup>th</sup> century and puts the sail directly over the
torso and ending at the base of the hips. Like the paddling and the quadrupedal
behavior, this is weird. Both <a href="http://translate.googleusercontent.com/translate_c?depth=1&hl=en&rurl=translate.google.com&sl=it&tl=en&u=http://theropoda.blogspot.com/2008/12/misteriosi-giganti-del-sahara-quarta.html&usg=ALkJrhiWtt4Afld07znHSzhzIAoM7Di95A"><span style="color: blue;">Cau</span></a>
and <a href="http://qilong.wordpress.com/2010/05/16/weekly-picture-3-spinosaurus-spines/"><span style="color: blue;">Headden</span></a>
have stated prior that the tall backwards-sloping dorsal neural spine should instead
be placed in the tail, as it’s much longer than any of the other dorsal neural
spines, has a backwards slope to it similar to what we see in caudal vertebrae,
and it better matches the sloping back of other spinosaurid ridges/sails. We’ll
have to see in the long run who’s right about this conundrum.</span></span></div>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Times,"Times New Roman",serif;"><i>Yummy, yummy, fishy, fishy...</i></span></td></tr>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Finally, and I just wanted to touch
on this a bit, I’m surprised about how little the possibility of other semi-aquatic
dinosaurs has been discussed in light of this discovery. Even Ibrahim and Sereno’s
team have stated that they think that <i style="mso-bidi-font-style: normal;">Spinosaurus</i>
was an “extreme evolutionary experiment” which went nowhere, and that dinosaurs
were almost all landlubbers. While it is true that terrestrial dinosaurs
represent the overwhelming majority, what about the proposed aquatic dinosaurs seen
in literature occasionally as of recent? <i style="mso-bidi-font-style: normal;">Thescelosaurus</i>?
</span><span style="font-size: 12pt;">CMN
8547?</span><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";"> <i style="mso-bidi-font-style: normal;">Lurdusaurus</i>?
</span><i style="mso-bidi-font-style: normal;"><span style="font-size: 12pt;">Opisthocoelicaudia</span></i><span style="font-size: 12pt;">? Heck, and what
about other spinosaurids? Did everyone forget about <a href="http://geology.gsapubs.org/content/38/2/139.short"><span style="color: blue;">this paper</span></a>?</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt;">Also,
since <i style="mso-bidi-font-style: normal;">Irritator</i> and <i>Oxalaia</i><span style="mso-bidi-font-style: italic;"> are close relatives to <i>Spinosaurus</i>,
shouldn’t we regard them as having similar anatomy as well? Both of them are only
known from skull material, and as </span>Michael Mortimer showed, two caudals
from the Alcantara Formation of Brazil were classified as <i>Sigilmassasaurus</i><span style="mso-bidi-font-style: italic;">. Since <i>Sigilmassasaurus</i></span> was just now found to be
synonymous with <i>Spinosaurus</i> and spinosaurid in nature, it’s likely that
they belong to</span><span style="mso-bidi-font-style: italic;"> <i>Oxalaia</i>.
Thus, it would make much more sense for them all to have a similar anatomy and
lifestyle rather than radically different anatomy, at least based on what we
know. So rather than a one-off, maybe <i>Spinosaurus</i> was part of a much
larger subfamily of semi-aquatic theropods which we’ve yet to discover?</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">Anyway, thanks for reading. As you
can see, it has been about eight months since I last made a post on here, and I
certainly regret not being able to. School has been extremely busy, and over
the summer I was out doing tons of extra work to prepare for college next
year. In an attempt to resurrect this blog and get back in the habit of posting
(while at the same time juggling tons of other work), I’ll try posting shorter
topics from now on, mixed in with occasional longer posts like this one.</span></span></div>
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<span style="font-family: Times,"Times New Roman",serif;"><span style="font-size: 12pt; mso-fareast-font-family: "Times New Roman";">As always, I’d love to hear
suggestions for future topics. I’m also now on <a href="https://www.facebook.com/tristan.stock.3"><span style="color: blue;">Facebook</span></a> and <a href="http://raptorx863.deviantart.com/"><span style="color: blue;">Deviantart</span></a>, so subscribe on there
if you want to discuss anything science-y with me or see my wonderfully amateur
artwork and other projects that I post. As always, stay sharp until next time!
Cheers!</span></span></div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com2tag:blogger.com,1999:blog-1718421695417441669.post-59438797522728057102013-11-13T00:24:00.000-08:002013-11-16T22:07:57.409-08:00SVP LA<div class="separator" style="clear: both; text-align: center;">
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As many of you already know, I attended the 73rd Meeting of the Society of Vertebrate Paleontology on Wednesday, Oct. 30 and Saturday, Nov. 2 and it was a positively thrilling experience to say the least. There were so many great discussions, presentations, discoveries, and people. I almost felt overwhelmed by the huge numbers of paleontologists, geologists, artists, and fellow bloggers I was able to meet at the event. I even got a few books signed, which was great. The Awards Banquet on Saturday was also especially inspiring and fun. There was only one downside which I should acknowledge: the cost. But it was really, truly worth every penny and I'm very grateful my parents allowed me to go.<br />
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Of course, the talks were the highlight of the event. I sadly missed the Thursday and Friday talks due to school, and thus was not there during the announcement of things like the Therizinosaur nesting colonies, T. rex having an Asia ancestry, an 11-ish meter Abeliosaurid from the late Cretaceous of Kenya, the bizarre new anatomy shown by a brand new specimen of <i>Deinocheirus</i>, and the possible resurrection of the genus <i>Brontosaurus.</i> I was fortunate to get updates on some of the talks by various people who were there the whole time, but I'll refrain from talking about them until properly published. Due to the fact that I saw so much new stuff, I'll try to make everything brief.<br />
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<tr><td class="tr-caption" style="text-align: center;"><h2>
<span class="Apple-style-span" style="font-size: xx-small; font-weight: normal;">New look for Deinocheirus<br />The neck, ridge, and legs all based on new info from SVP.</span></h2>
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<b><u>Wednesday, Oct. 30:</u></b> We first saw talks on growth and ontogeny in dinosaurs, such as some new discoveries and methods being used to settle the infamous "Toroceratops" debate, and new juvenile, neonate, and embryonic specimens from some familiar dinosaurs like <i>Chasmosaurus</i>, <i>Troodon</i>, and <i>Allosaurus</i>. Growth, in my opinion, is one of the most interesting things about extinct animals, and the fact that dinosaurs spent so much of their life as juveniles leads to interesting topics about their ecology, behavior, and biology. Thus, I was extremely satisfied to learn about the growth rates, peak performance, and sexual maturity in <i>Troodon</i>, <i>Maiasaura</i>, and <i>Diplodocus</i> respectively. Dial had a wonderful talk about birds and how the locomotor changes in their ontogeny may effect what we know about bird evolution, and finally there was a presentation on multi-niche ontogeny, and how it affected the survivorship ability of numerous animal groups across the K-T boundary.<br />
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On the way out of the presentation halls, I was lucky enough to run into and have a short chat with Dr. Darren Naish, who's been a big influence on me to start up blogging and get into the whole scientific community in the first place. Even more of a shock was when he said he had seen my blog before! It was an honor to finally meet him after reading so many of his articles, and later at the Welcome Reception we had a short chat about <a href="http://www.pnas.org/content/early/2013/10/02/1316979110.abstract">Jehelornis' cool new tail feathers</a> and he signed my edition of <a href="http://www.amazon.com/Tetrapod-Zoology-Book-Darren-Naish/dp/190572361X">TetZoo Book 1</a>. I was also able to briefly meet Dr. Jack Horner, while a fellow dinosaur pal of mine attended Day One of the conference and chatted with him for quite a bit.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYgKfGa20kv0HMUia5q3IFCpAFB_5ibNtOym1jJqsRZgPuizbMDv4iPrDOgKWNpMhXJyUPWpFHoZAiVqa0MqgASS0R9_2nLdck57LMDXq5_-f9zSiWqRNKEeqf1hnFhNoIi9IZeMEWvf3J/s1600/photo+(4).JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYgKfGa20kv0HMUia5q3IFCpAFB_5ibNtOym1jJqsRZgPuizbMDv4iPrDOgKWNpMhXJyUPWpFHoZAiVqa0MqgASS0R9_2nLdck57LMDXq5_-f9zSiWqRNKEeqf1hnFhNoIi9IZeMEWvf3J/s1600/photo+(4).JPG" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: xx-small;">Me (left), Dr. Darren Naish (middle) and my good friend Irlanda (right).</span></td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbDYih0D6_o_C9aS1KsCs0pozQQxml2iHkaUCRlHAfW38nsZRWfwz9WeJ0ELfDeIGHWDjmWTZvJgz_i2Mh8Y_cqGZALyQrqFikckLfYA5XlcMzDST3otnpe-YnHW6fwbdGstBVtQfRDhEn/s1600/photo+(2).JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbDYih0D6_o_C9aS1KsCs0pozQQxml2iHkaUCRlHAfW38nsZRWfwz9WeJ0ELfDeIGHWDjmWTZvJgz_i2Mh8Y_cqGZALyQrqFikckLfYA5XlcMzDST3otnpe-YnHW6fwbdGstBVtQfRDhEn/s1600/photo+(2).JPG" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: xx-small;">Another pic with Me, Dr. Jack Horner, and Irlanda</span></td></tr>
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We then grabbed lunch, I looked at a few of the posters up in the poster hall, met Dr. Donald Prothero and got a brand new hardcover edition of <a href="http://www.amazon.com/Abominable-Science-Origins-Nessie-Cryptids/dp/0231153201">Abominable Science</a> signed by him, chatted with Luis V. Rey for a bit and bought one of his art pieces, chatted with Paul Sereno about <i>Eoraptor</i>, and introduced myself to Dr. Thomas Holtz before the afternoon session. During that session they covered everything from the evolution of the ankylosaurid tail club, to a new species of basal neoceratopsian from the Cloverly Formation with a really awesome beak, an articulated baby <i>Chasmosaurus</i> with skin impressions, and a talk about pachycephalosaur respiratory turbinates I was excited about just to name a few.<br />
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After that we attended the Welcome Reception at the LA County Museum of Natural History (the same one where I volunteer), where we talked with Dr. Luis Chiappe (curator and director of The Dinosaur Institute) briefly before he continued to greet the many guests. I also got to meet artist and fellow blogger <a href="http://www.skeletaldrawing.com/">Scott Hartman</a> and me, my mom, and friend Irlanda all found people to chat with. After a while the Museum's famous dinosaur puppets came out to greet everyone. They're a T.rex named Hunter and a Trike named Dakota, both of which are juveniles. Everyone was mesmerized by the models. I am lucky I get to see them weekly.<br />
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We left the reception tired yet satisfied after having a wonderful experience. Sadly, due to schoolwork I was unable to return to SVP on either Thursday or Friday, and the fact that Halloween was the following day didn't help either. But I worked really hard to get all my work done so that I could return on Saturday, and a lot more fun ensued then.<br />
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<u style="font-weight: bold;">Saturday, Nov. 2:</u> I faced a dilemma when I got to SVP on Saturday. I couldn't decide which one of the morning sessions I should attend: the one on Polar animals, or the one on paravians and avians. I decided on neither, and ran into the mammal session which was starting. Luckily, the talk was on canids, and I coincidentally had just finished reading Wang and Tedford's <a href="http://www.amazon.com/Dogs-Fossil-Relatives-Evolutionary-History/dp/0231135297" style="font-style: italic; text-decoration: underline;">Dogs: Their Fossil Relatives and Evolutionary History</a> a few days prior, so I had an interest in the topic. They talked about how the ankle bone could be used to gauge certain species of canid's hunting behaviors and find out if they were ambush, pounce, or pursuit predators. I found the topic very interesting to say the least, and they had some very interesting interpretations about the evolution of modern wolf hunting.<br />
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<tr><td style="text-align: center;"><a href="http://www-tc.pbs.org/wnet/nature/files/2008/08/610_ag_graywolf1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="162" src="http://www-tc.pbs.org/wnet/nature/files/2008/08/610_ag_graywolf1.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: xx-small;">According to the talk given, modern pursuit hunting typical of Grey Wolves<br />might have been a recent invention. Previous species used other methods of hunting.</span></td></tr>
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After I got mammals out of my system, I started running between the two other halls for the rest of the morning, trying to catch everything that looked of interest from the abstract. I saw everything from new specimens of <i>Anchiornis</i> with new anatomical details, a possibly secondarily flightless <i>Archaeopteryx</i>, the pterosaur from Antarctica that I mentioned briefly in my magazine article from early this year, new species of dinosaurs from both the North and South Poles, and new methods of scanning feathered dinosaurs for melanin preservation. Everything was incredibly interesting, but sadly, the talk about the newly discovered Siberian Ornithischian with feather-like integument was canceled at the last moment, which was disappointing to say the least for everyone.<br />
<br />
However, another discovery from Alaska made me perk up once again. A new species of tyrannosaur was discovered in Prince Creek and is the apparent owner of the tooth material that has been discovered up there for the last few years. What's really interesting about it though is that it was suggested that it exhibits insular dwarfism, as it has a 600 mm skull (which is tiny for a tyrannosaur) yet shows signs of being fully grown. What implications this has for its biology and the ecology in the region has yet to be shown, but I find myself really liking this guy so far. Might be my new favorite dinosaur when he's properly named. :)<br />
<br />
<span class="Apple-style-span" style="font-family: inherit;">After the morning talks, we grabbed lunch and looked at all the posters in the poster hall. I got to meet and had a nice chat with Duane Nash from <a href="http://antediluviansalad.blogspot.com/">A<span class="Apple-style-span" style="line-height: 16px;">ntediluvian Salad</span></a> and <a href="http://southlandbeaver.blogspot.com/">Southland Beaver</a>, who wrote a post that was a big inspiration for my <a href="http://www.youtube.com/watch?v=JuYo5-YuAoM">Kem Kem video</a> I made awhile back. I walked over to a souvenir table with numerous pins of extinct animal skulls on it. I tried to identify them all, but failed horribly when it came to identifying the <i>Champsosaurus</i> skull (I need to read more literature about those guys...). Finally I settled on purchasing an awesome pewter <i>Styracosaurus</i> pin, which now accompanies me every day I work at the museum.</span><br />
<span class="Apple-style-span" style="font-family: inherit;"><br /></span>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/0/03/Champsosaurus_BW.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="172" src="http://upload.wikimedia.org/wikipedia/commons/0/03/Champsosaurus_BW.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: xx-small;">First time I ever misidentified an extinct animal's skull.<br />Damn you, <i>Champsosaurus</i>...</span></td></tr>
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<span class="Apple-style-span" style="font-family: inherit;">The last sessions I attended were on a broad range of topics concerning various groups of reptiles from pterosaurs to icthyosaurs to turtles. The first talk was on the first Triassic pterosaur from North America, which was awesome because I always wanted to know what kinds of pterosaurs <i>Ceolophysis</i> was seeing in its environs. (<i>Peteinosaurus</i> is from Italy, not North America, contrary to WWD.) Then there were talks about the diversity of Early Triassic Icthyosaurs, the evolution of large eyes in Icthyosaurs, and many talks about the <span class="Apple-style-span" style="font-family: inherit;">diversity and evolution of all kinds of turtles, and even some stuff on the Leatherback evolution (and a short bit on conservation, which my mom really enjoyed). They then ended the event on the discovery of the first procolophonid from Tanzania, and although I don't really study procolophonomorphs, I was still thoroughly interested in the topic.</span></span><br />
<span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="font-family: inherit;"><br /></span></span>
<span class="Apple-style-span" style="font-family: inherit;"><span class="Apple-style-span" style="font-family: inherit;">I then walked around for a bit, read some more posters on a possible new species of <i>Edmontosaurus</i> from Prince Creek and a fossil Rhino from Japan, chatted with someone about Dire Wolves, saw Mark Norell but didn't have a chance to say hi, and quickly ran downstairs to freshen up before the Awards Banquet. We sat down at a table with a bunch of students from Florida State University, and I got to chat with one of them about her graduate work concerning South American mega herbivores. They then started the presentation, and it was extremely inspiring for me. They honored paleontologists who had sadly passed earlier in the year, awarded some student scholarships, honored filmmaker Steven Spielberg (although sadly he could not attend) for his support of young paleontologists through his Jurassic Foundation, played clips from old dinosaur movies, handed out more awards, and finally the event ended with a speech given by Dr. Jack Horner, who was awarded th<span class="Apple-style-span" style="font-family: inherit;">e </span></span></span><span class="Apple-style-span" style="line-height: 19px;"><span class="Apple-style-span" style="font-family: inherit;">Romer-Simpson Prize for Lifetime Achievement — the highest honor one could receive from the Society.</span></span><br />
<span class="Apple-style-span" style="line-height: 19px;"><span class="Apple-style-span" style="font-family: inherit;"><br /></span></span>
<span class="Apple-style-span" style="line-height: 19px;">After the banquet, we stopped into the after hours party but the atmosphere was not very conducive to chatting, so we called it a night. The entire way home I felt inspired and overjoyed to have had the chance to attend a world-class paleontology conference here in my own backyard and to be a member of such a prestigious society. I dream that I'll eventually be up there on a podium one day presenting my discoveries to the world. Until then, you can still catch me blogging here!</span><br />
<span class="Apple-style-span" style="line-height: 19px;"><br /></span><span class="Apple-style-span" style="line-height: 19px;">Stay sharp everybody!</span>Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com1tag:blogger.com,1999:blog-1718421695417441669.post-66299475285264168232013-10-19T10:36:00.002-07:002013-10-19T10:36:26.451-07:00Disneyland for Dinosaur Nerds<div class="separator" style="clear: both; text-align: center;">
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzAHxioawIfsmacP_WhrgmK4aBJv6RHJYFipy4MtpsGlfFelJKbmn3kkRqykEGWiIqZDRIDp9zbh-zlGjTL_z1jH5xsqM0N8DcqPjlhnf17KGLTBS1BfDMY729Me7u3PN-dNQKLE2oDwAN/s1600/stegoceras-validum%5B1%5D.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzAHxioawIfsmacP_WhrgmK4aBJv6RHJYFipy4MtpsGlfFelJKbmn3kkRqykEGWiIqZDRIDp9zbh-zlGjTL_z1jH5xsqM0N8DcqPjlhnf17KGLTBS1BfDMY729Me7u3PN-dNQKLE2oDwAN/s320/stegoceras-validum%5B1%5D.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-size: xx-small;"><i>Stegoceras validum</i> by <a href="http://johnconway.co/">John Conway</a><br />Why didn't you tell me you had respiratory turbinates!?</span></td></tr>
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My loyal readers, I must first start off by apologizing for not writing a post last month. Getting back into the swing of things at school, as well as my docent job at the LA Museum of Natural History and writing a new Magazine article, has made it hard for me to find the time to post here. It also doesn't help that during the short time that I do get on the net, I find myself getting caught up in long discussions with people on Forums or YouTube comment sections, or reading long posts by numerous people in the Paleontology Blogging community. (I'm looking at you, Naish...)<br />
<br />
It's been incredibly busy with my Museum job, with our team hosting various events coming up like RAAD (Reptile and Amphibian Appreciation Day) and the Haunted Museum. Moreover, with holidays like Halloween, Thanksgiving, and Christmas right around the corner, I fear my posts will be sporadic on here for a while. But don't fret, when I post it will be because I have something worthwhile to say. In fact, today I have some great news for you all.<br />
<br />
The museum I just so happen to volunteer for is hosting the Society of Vertebrate Paleontology (SVP) meeting from October 30th to November 2nd in Los Angeles. I will be attending one day of the conference with a friend and will be able to see first-hand what numerous paleontologists have been working on, before it has even been put in print yet. I'm extremely excited and have already read much of the info concerning the event on the Program and Abstracts, which you can read <a href="http://vertpaleo.org/PDFS/88/887c249a-e0b1-46ee-8393-221f0574c8a3.pdf">here</a>.<br />
<br />
I plan to be there on the day there will be some interesting discussions on Dinosaur Ontogeny and Ornithischian studies, at the cost of missing the discussions on Theropods and Polar Animals. Still, what I am going to be seeing is a lot of cool stuff that I'll definitely try to write about here as I'm able.<br />
<br />
There is going to be information on the peak performance and mortality in Maiasaura, Triceratops growth (including the "Toroceratops" debate), baby Troodons, and *shock horror* Allosaurus eggs <i>and</i> embryonic remains from the Morrison! And that's just the morning! There's also all kinds of info on ankylosaur, ceratopsian, and pachycephalosaur anatomy and evolution in the afternoon, including a major announcement concerning <span class="Apple-style-span" style="font-family: inherit;">nasal turbinates!!!</span><br />
<br />
Nasal turbinates are a major discovery (well, at least in my opinion) because they are often seen as an indicator of endothermy in animals which have them (although if I'm remembering correctly, ratites and a few other birds lack them). They've so far been said to be absent in dinosaurs, and thus some scientists will often say that this is an indicator that dinosaurs were ectothermic like lizards (however, as they are very fragile and decompose almost as fast as cartilage and other soft tissues, this lack of them in the fossil record may not be a surprise). If there truly are turbinates in Pachycephalosaurs, it would be a major discovery and would suggest that dinosaurs as a whole (or at the very least Pachycephalosaurs) were endothermic, and it would also have implications for the breathing and olfactory abilities in these animals.<br />
<br />
So yeah, I'm extremely excited about all this, and do note that this is just the day that I'm visiting. Looking through the whole list, there's a whole lot more presentations on all types of other animals that I'll sadly be missing, but look exciting and interesting nonetheless, and I can't wait to read about them all when they come out in print. The most notable of sessions I'll be missing is the announcement of what seems to be a new species of polar Ornithischian dinosaur from Siberia with *shock horror* preserved integument showing feathers! We're coming closer and closer to that fuzzy Ankylosaur by the day. :P<br />
<br />
Anyway, that's all for now. When I get back from SVP I'll make a follow-up post of everyone and everything I saw. Until then, stay sharp! :)Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-61145996574665765072013-08-30T22:48:00.000-07:002013-08-30T22:48:15.815-07:00Thyreophora + Xenarthra = Fuzzy Ankylosaurus?<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_77ZbrM_BstzUA-BI6lQs8-VHC3LIHcwFewjW2bimcdpIwk4Y7pLP7EiUm1ZAtlV_6mdZw3Wufa5_Z2Ae7xAMjzo6MR9vBVBNuZhCivaqf7cSsrI-T_JLEASq0uTIRj0wTVpFgbmywPN3/s1600/Ankylosaurus+Tongue.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="310" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_77ZbrM_BstzUA-BI6lQs8-VHC3LIHcwFewjW2bimcdpIwk4Y7pLP7EiUm1ZAtlV_6mdZw3Wufa5_Z2Ae7xAMjzo6MR9vBVBNuZhCivaqf7cSsrI-T_JLEASq0uTIRj0wTVpFgbmywPN3/s400/Ankylosaurus+Tongue.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Beautiful amateur artwork by yours truly. But why the fuzz?</span></td></tr>
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For those of you who have been checking <a href="http://www.youtube.com/user/RaptorX863?feature=mhee">my YouTube page</a>, you may have noticed that I posted a new video, this time about <a href="http://www.youtube.com/watch?v=UreBVvMtmJc">the anatomy of the Ankylosauria</a>. In it I talk about everything ankylosaur, as well as include an image by yours truly showing some speculative interpretations of their hyoids. However, in that same image I also portrayed the ankylosaur, which was based on <em>Ankylosaurus magniventris</em>, with feather-like protofeathers (a.k.a. dinofuzz or whatever it's called these days). Some people might think that this is due to scientists' current preoccupation with taking every dinosaur and slapping some feathers onto it, shattering the hearts of so many JP fans. However, I actually have a very good reason why I believe that not just <em>Ankylosaurus</em> might have had feathers, but also that it might be likely that the entire Thyreophora might've had such fuzz, even more than other large-bodied dinosaur groups. It starts with observations of another living group of animals: the Xenarthra.<br />
<br />
Xenarthra are a group of mammals exclusive to the Western Hemisphere. They include freaky animal families like Armadillos, Sloths, and Anteaters, as well as awesome extinct forms like Ground Sloths and Glyptodonts. They are bizarre on so many accounts relating to their anatomy, such as having vertebrae that articulate differently than any other mammal, their lack of tooth enamel, and don't even get me started about some of their unsavory habits, like the recently documented observations of Linnaeus's two-toed sloth drinking from human latrines (Heymann 2010). Yuck...<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/9/9b/Choloepus_didactylus_2_-_Buffalo_Zoo.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="275" src="http://upload.wikimedia.org/wikipedia/commons/9/9b/Choloepus_didactylus_2_-_Buffalo_Zoo.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">It suddenly seems a lot less cute after discovering about its drinking habits.</span><br />
<span style="font-size: xx-small;">I wonder how Kristen Bell reacted to that discovery...</span></td></tr>
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Anyways, these guys seem to share some aspects of their physiology with thyreophorans, and no I'm not just saying that because they both have members that are complete turtle-mimics. Xenarthra are interesting in that they have the lowest body temperature and metabolic rates of any mammal, being at 40 to 60% what you would expect for mammals of their size (McNab 1980). This low body temperature makes xenarthrans somewhat slow-moving animals, and they have to face problems many people would typically associate with reptiles, such as having to regulate their body temperature and suffer a slower growth rate than other mammals. The latter trait is particularly important, as it's a trait also shared by thyreophorans.<br />
<br />
The thyreophoran taxa <em>Scutellosaurus</em> (Padian 2004), <em>Stegosaurus</em> (Redelstorff 2009), and numerous American ankylosaurs (Stein 2013) have all been shown to have slowed growth rates when compared to other dinosaurs. They weren't as slow as reptiles, but definitely not as fast-growing as mammals. This suggests that like xenarthrans, the Thyreophora had a metabolism slower than other dinosaur families. There is, however, the exception of <em>Kentrosaurus</em>, which might have had a faster growth rate (Redelstorff 2013). However, <i>Kentrosaurus</i> seems to have been an exception, and the majority of evidence points towards thyreophorans having lowered body temperatures like xenarthrans. Whether or not their actual body temperatures were at comparable levels to xenarthrans we don't know, but seeing as how many scientists now consider dinosaurs to be warm-blooded on the same level as modern mammals, similar thermoregulatory levels between thyreophorans and xenarthrans might be expected. I'd like to see someone try to test this idea in the future.<br />
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So, what does this all have to do with an <em>Ankylosaurus</em> having fuzz? Well, everything really. You see, the main argument made by people against the idea that large dinosaurs had feathers, or any type of fuzz really, is that they wouldn't need it, being large enough to be able to have a stable body temperature, as seen on modern large mammals. I have my own issues with this idea, since it assumes that protofeathers and hair are the same kind of structure (which they are not), and that dinosaurs have a similar physiology to mammals (which is unlikely). However, even assuming such ideas, we still know of large-bodied mammals that live in tropical regions which have thick, shaggy fur, and they're xenarthrans.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/6/63/Nothrotheriops.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="260" src="http://upload.wikimedia.org/wikipedia/commons/6/63/Nothrotheriops.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">The Shasta Ground Sloth, a desert-dwelling sloth that was completely covered in shaggy fur.</span><br />
<span style="font-size: xx-small;">Other members of the group were the size of an Elephant and just as fluffy.</span></td></tr>
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Ground sloths are already so famous that they don't need an introduction. They are giant ground-dwelling sloths that were running around on the sides of their feet during the Ice Age, and alongside mammoths, were the largest animals in their environment. However, despite their size, they're often portrayed as being very fuzzy animals with shaggy fur. When in a discussion with someone the other day, they dismissed this as simply an assumption and asserted they were probably hairless like elephants. This is poppycock. We have mummified ground sloth skin from caves in Arizona, Nevada, Argentina, and Chile which show thick fur on the animals. We even have them preserved for <em>Eremotherium</em>, which was the size of a small elephant, and its likely that the fur is present in still larger members like<em> Megatherium</em>.<br />
<br />
So this would seem contrary to what people say about large mammals shedding fur at larger sizes. Why did ground sloths keep their shaggy fur in tropical environments at such large sizes while other groups of mammals of equivalent size lost their fur? Our best answer is that this was due to their lowered metabolism, which means they had a harder time holding onto body heat than other mammals. Apparently holding onto that hair was also a pretty smart move, especially since ground sloths back then were perfectly able to extend their range up into temperate regions of North America and even as far north as Alaska during the last Ice Age, while living sloths have trouble tolerating even temperate latitudes. According to McNab, this was probably due to a combination of their thick fur, as well as greater size, larger muscle mass, and a constant food supply compared to their living relatives (McNab 1985).<br />
<br />
So assuming that ankylosaur growth rates suggest that they had lowered body temperatures like xenarthrans, might we then expect that these guys were covered in shaggy fuzz, too?<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2013/6/10/1370872166641/Lo.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2013/6/10/1370872166641/Lo.jpg" width="286" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><em>Stegosaurus</em> with tail spines made of porcupine-like filaments. Art by Mark Witton.</span><br />
<span style="font-size: xx-small;">Looks like other scientists got the memo, or they're just slapping feathers on everything again...</span></td></tr>
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Thus, even assuming that they had a physiology similar to mammals, and the falsified assumption that protofeathers were similar to hair, our knowledge of their possible xenarthran-like metabolism would still make them candidates for long filaments covering their entire body. We also know that ankylosaurs at least lived in temperate environments, such as Liaoning, and polar environments like Alaska, Australia, and New Zealand. These guys would've needed even longer fur in order to survive the cold snaps, if they were xenarthran-like in their metabolism.<br />
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When you take all this into account, it almost makes the picture I drew kind of conservative, showing only short fuzz compared to the longer hair common on ground sloths. Perhaps I'm diving too deep into speculation right now, but I think that my idea holds some merit. What are your thoughts? As always I'd love to hear everyone's opinion on this.<br />
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Stay sharp! And make sure you check out my brand new Ankylosaur video on YouTube:<br />
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.youtube.com/embed/UreBVvMtmJc?feature=player_embedded' frameborder='0'></iframe></div>
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<strong><u>References:</u></strong><br />
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Heymann, E. W., Flores Amasifuén, C., Shahuano Tello, N., Tirado Herrera, E. T. & Stojan-Dolar, M. 2010. Disgusting appetite: Two-toed sloths feeding in human latrines. <em>Mammalian Biology</em> doi:10.1016/j.mambio.2010.03.003<br />
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<span class="reference-text"><span class="citation journal">McNab, Brian K. (November 1980). "Energetics and the limits to the temperate distribution in armadillos". <i><a href="http://en.wikipedia.org/wiki/Journal_of_Mammalogy" title="Journal of Mammalogy">Journal of Mammalogy</a></i> (<a href="http://en.wikipedia.org/wiki/American_Society_of_Mammalogists" title="American Society of Mammalogists">American Society of Mammalogists</a>) <b>61</b> (4): 606–627. <a href="http://en.wikipedia.org/wiki/Digital_object_identifier" title="Digital object identifier">doi</a>:<a class="external text" href="http://dx.doi.org/10.2307%2F1380307" rel="nofollow">10.2307/1380307</a>. <a href="http://en.wikipedia.org/wiki/JSTOR" title="JSTOR">JSTOR</a> <a class="external text" href="http://www.jstor.org/stable/1380307" rel="nofollow">1380307</a>.</span></span><br />
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McNab BK (1985). Energetics, population biology, and distribution of Xenarthrans, living and extinct. In: Montgomery GG (Editor), <i>The Evolution and Ecology of Armadillos, Sloths and Vermilinguas</i>. Smithsonian Institution Press, Washington and London, 219-232.<br />
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<a href="http://www.blogger.com/null" id="pone.0068590-Padian2" name="pone.0068590-Padian2"></a><span style="font-family: inherit;">Padian K, Horner JR, Ricqlès A (2004) Growth in small dinosaurs and pterosaurs: the evolution of archosaurian growth strategies. J Vert Pal 24: 555–571. doi: </span><a href="http://dx.doi.org/10.1671/0272-4634(2004)024[0555:gisdap]2.0.co;2"><span style="font-family: inherit;">10.1671/0272-4634(2004)024[0555:gisdap]2.0.co;2</span></a><span style="font-family: inherit;">.</span><br />
<span style="font-family: Trebuchet MS; font-size: x-small;"><span style="font-family: Trebuchet MS; font-size: x-small;"><span style="font-family: inherit; font-size: small;"></span><br />
<span style="font-family: inherit; font-size: small;">Ragna Redelstorff & P. Martin Sander (2009) Long and girdle bone histology of Stegosaurus: implications </span><span style="font-family: inherit;"><span style="font-size: small;">for growth and life history, Journal of Vertebrate Paleontology, 29:4, 1087-1099, DOI: <span style="color: blue;"><span style="color: blue;"><span style="color: blue;">10.1671/039.029.0420</span></span></span></span></span><br />
<span style="color: blue; font-family: inherit; font-size: small;"></span><br />
<span style="font-family: inherit; font-size: small;">Redelstorff, R., Hübner, T. R., Chinsamy, A. and Sander, P. M. (2013), Bone Histology of the Stegosaur <em>Kentrosaurus aethiopicus</em> (Ornithischia: Thyreophora) from the Upper Jurassic of Tanzania. Anat Rec, 296: 933–952. doi: 10.1002/ar.22701</span><br />
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Stein M, Hayashi S, Sander PM (2013) Long Bone Histology and Growth Patterns in Ankylosaurs: Implications for Life History and Evolution. PLoS ONE 8(7): e68590. doi:10.1371/journal.pone.0068590</span></span></span>Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com7tag:blogger.com,1999:blog-1718421695417441669.post-25846416346286452422013-07-26T22:20:00.000-07:002013-07-26T22:24:12.188-07:00Pacific Rim and Kem Kem's Water-Loving Theropods<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://www.pacificrimmovie.net/wp-content/uploads/pacific-rim-movie-banner-striker-eureka-jaeger-vs-kaiju.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://www.pacificrimmovie.net/wp-content/uploads/pacific-rim-movie-banner-striker-eureka-jaeger-vs-kaiju.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><em>Striker Eureka vs. Otachi in a promotional poster for Pacific Rim</em></td></tr>
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I just went to see the new blockbuster Action/Sci-Fi/Mecha,/Kaiju movie <i>Pacific Rim</i> on Wednesday, and by God it was awesome. It was by no means the best movie ever, being plagued with numerous stereotypes and clichés (and I heard some complaints of bad acting, but I didn't really notice that when I watched it), but for the most part it stood up very well. It had great CGI, cool Kaiju and Jaeger designs, and it knew exactly where, when, and what to do to please the audience, so I found myself thoroughly enjoying the experience, and I recommend the film to everybody even remotely interested in the concept. You won't leave the theater disappointed.<br />
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Director Guillermo del Toro took his inspiration from Japanese animes and Kaiju movies, and I could definitely see the resemblance to the former. I watch anime when I can, and many of the characters in Pacific Rim (despite undoubtedly being stereotypes) had an uncanny resemblance to characters in animes I had seen before. This was probably intentional on Guillermo's part. I also noticed some resemblances to <a href="http://en.wikipedia.org/wiki/Neon_Genesis_Evangelion_(anime)">Evangelion</a>, an anime series with a similar story of giant monsters called Evas fighting human-powered mechas in order to protect the world. Other people have also noticed the similarities, but apparently Guillermo had never seen Evangelion, so all these parallels are probably coincidental.<br />
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Despite having seen numerous animes though, I've barely seen any Japanese Kaiju films before, so I couldn't see if there were any parallels there (other than, well, the fact they both have giant Kaiju in them). Maybe after seeing this movie it will encourage me to start watching some more Kaiju films. Hmm, I have always wanted to watch the original Godzilla movie.<br />
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Here's a funny story though. I've been watching another anime right now called <a href="http://attack%20on%20titan/">Attack on Titan</a>. It's about giant humans called Titans that eat normal-sized people alive just for fun, and how the last piece of humanity has been driven back into the dark ages and forced to retreat behind three giant walls that were built to keep the Titans out, but that's besides the point. The main antagonist's name in that show is Eren Jäger, whose last name has the same root as Pacific Rim's mechas, both being derived from the Germanic word for hunter (<strong><em>Jäger)</em></strong>. <strong>*Spoiler Alert*</strong> This is also ironic seeing as mid-way through the show Eren learns he has the ability to transform into a Titan, and he uses his power in order to fight off the Titans as they slowly try to break their way past the walls to devour the people hiding within. So all in all, Attack on Titan and Pacific Rim are both about giants trying to annihilate the human race and both have heroes named Jaeger that are trying to protect what's left of it. Kind of left me confused...<strong>*Spoiler Ends*</strong><br />
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There was, however, one HUGE problem with Pacific Rim that seriously brought down the movie for me. Watch this scene and you'll know what it is:<br />
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<span style="font-size: x-large;">LIES!!!</span></div>
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Eh, I would devote this whole post to ranting about that one scene, but luckily, <a href="http://blogs.scientificamerican.com/tetrapod-zoology/2013/07/25/tet-zoo-guide-to-pacific-rim/">Darren Naish on Tetrapod Zoology did it for me</a>, as well as talk about a lot of other cool aspects of the movie. Be sure to check that out when you can.<br />
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Now, onto important science-y things...<br />
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I made another video a few days ago which I posted on YouTube, this one concerning the Kem Kem beds in Morocco. I was inspired to make this due to a lot of work being published on those beds, notably a paper that came out a few months back by Emilie Läng and others, called <strong><u><a href="http://www.sciencedirect.com/science/article/pii/S0031018213001855">Unbalanced food web in a Late Cretaceous dinosaur assemblage</a></u></strong>. I was able to read it about two weeks ago and was inspired to look more into the ideas presented. I then learned that Dale Russel suggested in 1996 a similar theory, I read <a href="http://antediluviansalad.blogspot.com/2012/09/planet-predator-ii-kem-kem.html">a post by </a><a href="http://antediluviansalad.blogspot.com/2012/09/planet-predator-ii-kem-kem.html">Duane Nash</a> at another small blog called <a href="http://antediluviansalad.blogspot.com/" target="post">Antediluvian Salad</a> on the topic, and I had a chance to watch an Attenborough documentary about the effects of the Salmon Run in Canada and what it does to the local predator populations. By the end of that, I had enough info for a video, so I made one. Voila:</div>
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It's an interesting idea, and while I'm not completely persuaded by all of its points, nevertheless I do like the theory and I have no particularly big reason to doubt it based on current evidence. Besides, the image of a Carcharodontosaurus ripping a shark out of the water is just dang cool. Land sharks vs. Sea sharks. :P<br />
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I've already gotten a lot of attention via PMs and comments about the theory, with people telling me why they agree or disagree with it. I'd like to hear your opinions about it too, so be sure to leave a comment and feel free to make a suggestion for future topics. Until next time...stay sharp, everyone! ;)</div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com2tag:blogger.com,1999:blog-1718421695417441669.post-83122541628029088652013-07-13T16:41:00.001-07:002013-07-13T18:38:47.463-07:00"Porpoise Turtles" and Repenomamus<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><em>Well, this goes right up there with Sharktopus, Dinocroc, and Pizza the Hut.</em><br />
<em>(Are you catching the movie references?)</em></span></td></tr>
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Marine reptiles are awesome. One of the "big three," as I like to call them, (the other two being Dinosaurs and Pterosaurs), marine reptiles are any group of reptiles that evolved into an aquatic niche. They include a number of unrelated groups, from giant marine squamates like Mosasaurs, to s<span dir="auto">auropterygian </span>Plesiosaurs, to living Marine Iguanas. I get the honor of seeing some of the best extinct marine reptile specimens in the world every week, at my local museum where I recently began to volunteer. It has both the world's most complete Mosasaur as well as the only known specimen of a pregnant Plesiosaur on display. It's a nerd's paradise. Hopefully I can take some pictures of the specimens to share with you in the future.<br />
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While I would like to discuss those specimens in depth, I'll have to do that at another time. Sea turtles are going to be the topic of today's post. What few realize is that sea turtles are the only marine reptile family known to have survived the K-T extinction into modern day. You're probably all familiar with the extinct giant sea turtles like <em>Archelon</em> and <em>Protostega</em>, which are within a family called the d<span dir="auto">ermochelyoidae, whose sole surviving representative is the Leatherback sea turtle (<em>Dermochelys coriacea</em>). However, recently on PLOS, a new member of the giant sea turtle family was announced, named <em>Ocepechelon bouyai</em>, which has to be one of the most awesome sea turtles I've ever seen.</span><br />
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<tr><td class="tr-caption" style="text-align: center;">A big, weird, and freaky skull.<br />
Almost hard to believe it comes from a turtle...</td></tr>
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<span dir="auto">Why is <em>Ocepechelon</em> so awesome? Because it is just plain freaky (but in a good way). When I first saw the artist's rendering above, I almost thought it was a fish-eating crocodilimorph like a <span dir="auto">Phytosaur (by the position of the nostrils), but after reading it was a turtle I was shocked. Its skull (which is sadly the only part we have from this giant) was more than two-feet long, elongated, and tubular, and a horny beak, while probably present, would've been extremely abbreviated and ineffective in capturing prey. The fact that this giant was found in late Maastrichtian rocks of Morocco makes it even more exciting, as we lack virtually any fossils from Late Cretaceous Africa.</span></span><br />
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<span dir="auto"><span dir="auto"><em>Ocepechelon's</em> living habits are even more amazing. The authors make a compelling case that this guy was a suction feeder, and they drew a huge number of adaptations for such a lifestyle. However, he is unique among tetrapods in apparently being a pipette-feeder, like seahorses and pipefish. While most suction feeders alive today have short, wide jaws to maximize water flowing into their mouth, these fish focus on smaller prey and pick them out of the water selectively. Apparently <span dir="auto"><span dir="auto"><em>Ocepechelon</em> fed in a similar way as seahorses and, to a lesser degree, beaked whales, which it shares numerous adaptations with as well. The latter features inspired the nickname I posted above: the Porpoise Turtle.</span></span></span></span><br />
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">So, great job to the researchers who discovered and described <span dir="auto"><span dir="auto"><em>Ocepechelon! </em>He's now officially my favorite Mesozoic sea turtle, and he's just further evidence that the Mesozoic was teeming with reptile diversity. A lot of recent research into other reptile groups outside of the big three also shows that virtually every reptile during the Mesozoic was doing great. We have fossil squamates, snakes, mesosaurs, crocodilians, and sphenodonts running around during the Mesozoic, doing all sorts of things. Almost makes me feel sad for small mammals, as they were the only Mesozoic group that had virtually no diversification. As with most everything, however, there were a few exceptions.</span></span></span></span></span></span><br />
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">There are a few really cool mammals that lived during the Mesozoic. <em>Repenomamus</em>, the dinosaur-eating mammal found in Yixian, is one of my favorites, as it has guts. These guys reached huge sizes compared to other mammals, exceeding ten pounds, which is a lot for a mammal back then. Not just that but one specimen was found to have a baby <span dir="auto"><em>Psittacosaurus</em> in its gut, showing that these guys ate dinosaurs. The four-episode Discovery television series "Dinosaur Revolution" had a few clips that included small mammals, such as the beaver-like <em>Castorocauda</em> and flying squirrel-like <em>Volaticotherium.</em> I understand they were also going to include a section on <em>Repenomamus</em>, but it<em> </em>got cut from the project. Nobody knows why the segment got scrapped, but my guess is because it included the now-dubious taxon <em>Raptorex kriegsteini</em>.</span></span></span></span></span></span></span><br />
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">Luckily, I was able to find a storyboard sequence of the scene on YouTube. </span></span></span></span></span></span></span><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">Enjoy, but be warned...I was ROTFL so much after watching this. :)</span></span></span></span></span></span></span><br />
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">Until next time, stay sharp!</span></span></span></span></span></span></span><br />
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Click here for Part 2:</div>
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<a href="http://www.youtube.com/watch?v=LAUY7BccB2w">http://www.youtube.com/watch?v=LAUY7BccB2w</a><br />
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<strong><u>References:</u></strong></div>
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Nathalie Bardet, Nour-Eddine Jalil, France de Lapparent de Broin, Damien Germain, Olivier Lambert & Mbarek Amaghzaz (2013) A Giant Chelonioid Turtle from the Late Cretaceous of Morocco with a Suction Feeding Apparatus Unique among Tetrapods. PLoS ONE 8(7): e63586. doi:10.1371/journal.pone.0063586</div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-49033016093660090912013-07-02T17:46:00.003-07:002013-07-02T17:46:45.154-07:00Awesome Pterosaurs and the Blog's Promo-Video<div class="separator" style="clear: both; text-align: left;">
Well as I said before, since I just finished up with school I am getting more free time to do more things, like write on here. However, recently I've been caught up in reading Mark Witton's new book Pterosaurs (which BTW, is probably the best book on these extinct reptiles to date, and I highly recommend it to anyone even remotely interested in them) and have not had the attention span to tear myself away and write a new post, and during the time that I wasn't reading, I was getting ready to submit my new-and-improved version of my article to AncientPlanet Online Journal.</div>
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However, to make up for the lost time, I decided to make a new video, which I posted on YouTube yesterday covering Pterosaur diversity. It includes some new scientific information revealed in the book, as well as coverage of many of the extremes of pterosaur diversity. Enjoy:<br />
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After I was done with that, I decided that I needed something to spice up my YouTube channel and get more publicity for my blog, but I couldn't put my finger one what. Then it hit me. I needed something to promote it: a promotion video! So, I decided to throw this together over the weekend and put it up earlier today. It's not the best video I've ever made, and I was limited to using only my Windows Movie Maker program (which isn't the best for these types of videos) but I'm still pretty proud of it and it's a good start.<br />
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If anyone here has a suggestion for a future blog post or video, or simply has a question they'd like to have answered, feel free to send it by me. As always, stay sharp! ;)</div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-39279849245066763472013-06-02T14:58:00.000-07:002013-06-08T07:14:39.604-07:00Psittacosaurus, Allosaurus, Baryonyx, Wulatelong, Aurornis and Torvosaurus. Oh my!<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">You lying fossil! I believed in you!</span></td></tr>
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It seems that within the last month paleontologists have been publishing a lot of new discoveries about some well-known dinosaurs, as well as discoveries from two new guys guy that I'll get to further down. Some of these discoveries have been of great interest to me, and it has encouraged me to write about it here before school ends and I get more free time to talk about other stuff.<br />
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<span style="font-size: xx-small;">*I don't want this blog to become a sort of news blog where people can come and hear about all the latest discoveries, but if there is something in the news that I find interesting, then I'll post about it. I won't be talking about every little news item, though.</span><br />
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To start off I wanted to talk about a heartbreaking discovery concerning <em>Psittacosaurus</em>. <em>Psittacosaurus</em> is a basal ceratopsian, and also currently holds the record of most known species of any non-avian dinosaur genus. It's also one of the best known dinosaurs, with hundreds of specimens that include details about its internal and external anatomy (even including color!), as well as its diet, ontogeny, and behavior. One of the greatest examples of the latter was the discovery of 34 juvenile <em>Psittacosaurus</em> nested underneath the body of the adult animal, for a long time considered to be one of the greatest examples of parental care among any dinosaurs. Until it was found to be a fake.<br />
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A re-analysis of the specimen in question by Zhao and associates found it to be a composite. The 34 juveniles and the 'adult' turned out to be glued together, and the 'adult' specimen in question wasn't even of reproductive age. All in all very disappointing, especially for myself, as the magazine article I've been writing for the last month happened to focus on this particular specimen, and with the news having been published four days before my article was due for publication, I was unable to revise it in time to make the deadline. That was really depressing for me, and I felt like I let a lot of people down. Updates are being made for the next issue, however. Or perhaps I'l focus on less-researched topic than dinosaur parental care, which is what I had originally planned. Perhaps I'll discuss discoveries of juvenile dinosaurs together in nests separate from adults. For instance, although the <em>Psittacosaurus</em> composite is no longer considered an example of parental care, the 34 juveniles still died together, and Zhao also talked about a new specimen which preserves multiple juveniles of differing age groups together, so there certainly are a lot of interesting points remaining to discuss.<br />
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In other news, Witmer Lab has been at it again. This time they reconstructed the neck musculature of <em>Allosaurus</em> using computer models and found that, unlike <em>Tyrannosaurus</em>, <em>Allosaurus</em> did not suffer from as much forward inertia. The lighter head allowed the head to swerve and move around faster than big, boxy-headed Tyrannosaurus and thus the animal was probably more agile. This also brings to mind one of my old <a href="http://tyranno-teen.blogspot.com/2012/01/predators-or-scavengers-locomotion-and.html">predator vs. scavenger posts</a>, where I said that T-rex suffered from a large amount of inertia and likely couldn't turn quickly. This was no problem for <em>Allosaurus</em>.<br />
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<span style="font-size: xx-small;">Animation by Witmer Lab. </span><span style="font-size: xx-small;">I own nothing. Forever alone....</span></div>
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Another interesting observation that they made was that they think they revealed the feeding style of this predator. Apparently unlike Tyrannosaurs, which are thought to have used their jaws to violently shake and tear off pieces of meat, <em>Allosaurus</em> seems to have used its jaw to slice off pieces of meat rather like a predatory bird. This really interests me as a study last year also reported that dromaeosaurids had a predation-style similar to eagles, restraining the prey with the limbs while slicing off pieces of meat with the jaw. Perhaps <em>Allosaurus</em> was doing a similar thing as dromaeosaurids, slicing off pieces of meat on large animals like sauropods and stegosaurs, eating them alive. Extremely gruesome and somewhat revolting, but an efficient feeding strategy nonetheless.</div>
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Onto another fan-favorite, remember <a href="http://tyranno-teen.blogspot.com/2012/12/anatomy-and-paleobiology-of-spinosaurid.html">my post about spinosaurids</a> a few month back? In it I talked about how Emily Rayfield conducted a study of a number of different theropods, including <em>Suchomimus</em>, and found something odd. Despite its length and lack of any notable features that would resist torsion, <em>Suchomimus</em> has a skull that could resist excessive force just as well as other large theropods. At first I thought that this was odd, and even she noted at the end of the paper that her numbers were inconclusive and required more in-depth studies, but now she and <span class="author" rel="dc:creator"><span class="person" property="foaf:name" typeof="foaf:Person">Andrew Cuff</span></span> have come back with a new paper that backs up this idea.<br />
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By using the skull of <em>Baryonyx</em>, a close relative of <em>Suchomimus</em>, they ended up with the same results. Not just that but they also cross-reference the skull with that of living crocodilians (an American Alligator, African Slender-snouted Crocodile, and <span dir="auto">Gharial) </span>and <em>Spinosaurus</em> and found that <em>Baryonyx</em> could withstand just as much torsion as some crocodilians and theropods, contrary to some studies suggesting that <em>Baryonyx</em> could only withstand as much torsion as a gharial. She also found that <em>Baryonyx's</em> skull reacted very different mechanically than a gharial, contrary to many other studies, including her own. One thing that really shocked me though was that she did find that <em>Spinosaurus'</em> skull reacted mechanically similar to that of a gharial, which again is contrary to some reports that it was better at withstanding mechanical forces than members of the Baryonychinae. Despite this, Rayfield and Cuff firmly state that when size is accounted for, both of the skulls "absolutely outperform all crocodilian taxa”.<br />
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I've yet to see how the paleontological community has reacted to this discovery, and it hasn't gotten much press, but now Rayfield and Cuff have suggested that perhaps the Spinosauridae as a whole might not have been obligate piscivores, but instead that perhaps diet was more reliant on size of the individual, as it is in living crocodilians. For example, juveniles crocodiles feed on small animals like fish and insects, mid-sized individuals mostly feed on fish and small game, and larger adult crocs mostly feed on land animals. This is an cool theory, and similar theories have been suggested for other theropods, so it certainly seems likely.<br />
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<tr><td style="text-align: center;"><a href="http://qilong.files.wordpress.com/2013/05/wulatelong-gobiensis-holotype-pes.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="273" src="http://qilong.files.wordpress.com/2013/05/wulatelong-gobiensis-holotype-pes.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Note the elevated toe claw.<br />
Bear in mind, this is a oviraptorid, not a Deinonychosaurian.</td></tr>
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<em>Wulatelong gobiensis</em> is a new species of basal oviraptorid from the Gobi Desert, and is the fifth new species of oviraptorid to be described this year. It's been a cool discovery not just because it is relatively complete, but it also seems to have died articulated in a relatively natural condition. However, the head and neck are preserved badly, and there aren't any unusual traits about it that make it stand out. It looks just like your average, run-of-the-mill oviraptorid at first glance, until you look down at the foot.<br />
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Although the original describers said nothing about it, images such as the one above clearly show that the second toe of this oviraptor has a large claw that is elevated off the ground. As I said, this specimen is articulated in a natural position, so it seems the claw was held in that position in life. If you don't know where I'm going with this, let me help you....<br />
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<strong>IT'S AN OVIRAPTORID WITH A DROMAEOSAUR-LIKE SICKLE TOE CLAW!</strong><br />
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Currently there has been a lot of talk about this specimen, and some scientists are even stating that it might have implications for the evolution of such enlarged hyperextendable claws, that perhaps the ancestor of oviraptorids and dromaeosaurids had such a structure, and even that the trait might be common throughout the Ceolurosauria. It's a bit of a mess right now, but the curious thing that myself and the paleontological community are shocked about is the fact that Xu Xing and the original describers of the specimen don't even remotely bring this up in their paper. It's strange. The animal is found articulated in its natural position showing the claw hyperextending like that, and there's no mention of it whatsoever? I hope we get to hear more about this guy and get a confirmation about such an amazing example of a non-Deinonychosaurian sickle claw. As for why an oviraptorid would need such a claw on its foot, I don't know, but here are some ideas:<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiauQBTsjmAb_UFCt428qIMfPY1EXav5BsIdfiikGaRQiL92v851mfE5kGWgZgPXr3C00XFGRtFdN780CDQsxRJzB60ZhNJCgsfS7YWowZ206ZlhDO1-tEZYyG0B2_t0zCf7eG8I_kY59k/s1600/Paraves+phylogeny.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiauQBTsjmAb_UFCt428qIMfPY1EXav5BsIdfiikGaRQiL92v851mfE5kGWgZgPXr3C00XFGRtFdN780CDQsxRJzB60ZhNJCgsfS7YWowZ206ZlhDO1-tEZYyG0B2_t0zCf7eG8I_kY59k/s400/Paraves+phylogeny.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">New relationships of basal birds. </span><span style="font-size: xx-small;">Time to start rewriting the text books.....</span><br />
<span style="font-size: xx-small;">Borrowed from <a href="http://theropoda.blogspot.com/2013/05/aurornis-xui-nuova-luce-sullorigine.html">Theropoda</a>.</span></td></tr>
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<span style="font-family: TimesNewRomanPS-ItalicMT; font-size: xx-small;"><span style="font-family: inherit; font-size: small;"><em>Aurornis xui</em> (and yes, it is named after Xu Xing, although to my knowledge he didn't work on the specimen) is a new species and genus of basal bird from the mid-Jurassic of China, and has dethroned <em>Archaeopteryx</em> as the "earliest bird" by about 15 million years. It's a pretty awesome discovery, as it provides a snapshot of how birds got their start, and in this case, has also provided a new area of analysis for researchers looking into the question of where <em>Archaeopteryx </em>falls on the theropod family tree. In this case, they found that it is more derived than <em>Aurornis</em>, and that it, along with <em>Anchiornis</em>, <span dir="auto"><em>Xiaotingia,</em> and <em>Rahonavis</em>(!) are all basal birds. Not just that, but they also found that the troodontidae are not closely related to dromaeosaurids or deinonychosaurians at all! Instead, they seem to be apart on an unnamed sister-group to the avialans, which would explain why troodontids share so many similarities with birds, more so than they share with dromaeosaurids.</span></span></span></div>
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However, despite this new find nobody should think of the chapter on </span><span style="font-family: inherit; font-size: small;"><em>Aurornis xui</em> as being closed, as I'm sure that in a few months we'll be getting another rebuttal paper stating some alternative ideas. The history of birds is filled with a lot of complex data, and we're at the point that defining birds as a group is harder than it looks, as there is literally no major differences between basal birds and other members of Paraves. We still have a lot more work to do, but having <em>Aurornis</em> with us will hopefully make it easier and not fuzzier.<br />
<br />Perhaps the most shocking find of all in this paper was the discovery that they made with Balaur bondoc. Apparently, it's not a dromaeosaurid; it's a basal bird and sister taxon to Pygostylia! That's a shocker, but there's good reason to think this is the case. The conclusion was based on a direct observation of the specimen, and a new monograph that came out that also came to this conclusion.<br />
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So, Balaur is some kind of Cretaceous dual-clawed killer dodo. That's going to take A LOT of getting used to...<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgloKp0NVDRRYeVzc_PkuZwZbfPiG00lmWm-sDFJBS-TmQoNdW3VRTwOeXSIViuKBwRwdHkU5W7XiuJJCcW9IAcmptRCo358HIwG9kbJZfPEEr8_6OSfwlCm0x6BmCZYj9WZIr9WTisqQ_u/s1600/srep01924-f1%5B1%5D.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span style="font-size: xx-small;"><img border="0" height="164" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgloKp0NVDRRYeVzc_PkuZwZbfPiG00lmWm-sDFJBS-TmQoNdW3VRTwOeXSIViuKBwRwdHkU5W7XiuJJCcW9IAcmptRCo358HIwG9kbJZfPEEr8_6OSfwlCm0x6BmCZYj9WZIr9WTisqQ_u/s320/srep01924-f1%5B1%5D.jpg" width="320" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">We FINALLY get some big theropod eggs and embryos!</span><br />
<span style="font-size: xx-small;">And look at them, such cute little baby <em>Torvosaurus</em>.....</span></td></tr>
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<em>Torvosaurus</em> was the largest predator in the Jurassic (ignoring Epanterias and Saurophaganax as they haven't been properly identified yet). This huge, heavily-built predator with serrated teeth, robust arms, and killer demeanor terrified most around it, but now we know that this species had quite a softer side, as <em>Torvosaurus</em> has now provided the first ever non-a<span dir="auto">vetheropod</span> eggs! Talk about a long wait! Nearly 200 years since the first Dinosaurs were described and 100 years since the first <span dir="auto">Maniraptor </span>eggs were discovered, and it's only now that we're getting some big theropod eggs? Fossilization is horribly bias sometimes, but I'm happy that we finally found them. Now we just need a t<span dir="auto">hyreophora and neoceratopsian nest and I can die peacefully.</span><br />
<span dir="auto"></span><br />
<span dir="auto">Moving on with this amazing find: These eggs are actually not THAT new; apparently they were first unearthed in 2005 but are only being described now. They were found in a clutch along a hillside and consist of a large number (exact number unknown) in the <span dir="auto">Lourinhã Formation in West Portugal. For those who are also dino-nerds, you'll remember that a clutch of eggs from the the Allosauroid/Coelurosaur <span dir="auto"><em>Lourinhanosaurus</em> were also found here. This might suggest that perhaps the area was favorable for breeding theropod females, or maybe that the fossilization process there is biased towards dinosaur eggs. Either way, somebody's got to check out that area for more of these clutches.</span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto">The microstructure of the eggs is also unique among theropods, as it has only one eggshell layer, while most theropods have two and birds have three. The eggs also seem to have been buried, as the openings in the eggshell are large to let in air, and the eggs themselves are not disturbed, suggesting that they were already buried by the mother. They were either buried in sediment or plant material, similar to what is seen in crocodiles, so perhaps parental care in this species was also crocodilian-like, but I'll save talking about that for my revised article. ;)</span></span></span><br />
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So, what's your favorite discovery in paleo-news recently? Feel free to share, and as always, stay tuned and stay sharp!<br />
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<strong><u>References:</u></strong><br /><br />
Cuff AR, Rayfield EJ (2013) Feeding Mechanics in Spinosaurid Theropods and Extant Crocodilians. PLoS ONE 8(5): e65295. doi:10.1371/journal.pone.0065295<br />
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Eric Snively, John R. <span class="notranslate"><span class="google-src-text notranslate" style="direction: ltr; text-align: left;">Cotton, Ryan Ridgely, and Lawrence M.</span> Cotton, Ryan Ridgely, and Lawrence M.</span> <span class="notranslate"><span class="google-src-text notranslate" style="direction: ltr; text-align: left;">Witmer (2013) Multibody dynamics model of head and neck function in <i>Allosaurus</i> (Dinosauria, Theropoda).</span> </span><span class="notranslate">Palaeontologia Electronica Vol 16, Issue 2, 11A 29pp.</span> <br />
<br />
<span style="color: black;">Godefroit P., Cau A., Hu D.-Y., Escuillié F., W. Wu, G. Dyke<span class="notranslate"> 2013.</span> <span class="notranslate"><span class="google-src-text notranslate" style="direction: ltr; text-align: left;">A Jurassic avialan dinosaur from China resolves the early phylogenetic history of birds. <i>Nature</i> doi:10.1038/nature12168</span></span></span><br />
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Qi Zhao, Michael J. <span class="notranslate"><span class="google-src-text notranslate" style="direction: ltr; text-align: left;">Benton, Xing Xu, and Martin J.</span> Benton, Xing Xu, and Martin J.</span> <span class="notranslate"><span class="google-src-text notranslate" style="direction: ltr; text-align: left;">Sander (2013) Juvenile-only clusters and behaviour of the Early Cretaceous dinosaur <i>Psittacosaurus</i>. </span></span><span class="notranslate">Acta Palaeontologica Polonica (in press) doi: <a href="http://dx.doi.org/10.4202/app.2012.0128">http://dx.doi.org/10.4202/app.2012.0128</a></span><br />
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Ricardo Araújo, Rui Castanhinha, Rui M. S. Martins, Octávio Mateus, Christophe Hendrickx, F. Beckmann, N. Schell & L. C. Alves (2013) Filling the gaps of dinosaur eggshell phylogeny: Late Jurassic Theropod clutch with embryos from Portugal. Scientific Reports 3 : Article number: 1924<br />doi:10.1038/srep01924<br />
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Xu X., Tan Q.-w., Wang S., Sullivan, C., Hone, D. W. E., Han F.-l., Ma Q.-y., Tan L. & Xiao D. 2013. A new oviraptorid from the Upper Cretaceous of Nei Mongol, China, and its stratigraphic implications. <em>Vertebrata PalAsiatica</em> 51 (2): 85–101.</span> </span>Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com1tag:blogger.com,1999:blog-1718421695417441669.post-21428673422724510382013-05-05T18:40:00.000-07:002013-05-05T18:40:35.154-07:00Walking with Dinosaurs: The 3D MovieFirst things first, I must apologize for about a month's absence in activity. I have currently been preoccupied by end-of-the-year work at school so my schedule has been really busy, and the rest of my time has been occupied by my magazine article work, family activities, and enlisting to volunteer at my local museum, so I haven't been able to find the time to write. Luckily, during the little free time I have had, I have been reading a lot of new books and scientific papers, so expect when all this is done to have a lot more posts by me.<br />
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However, that isn't why I'm here right now. I'm posting to talk about something awesome that was announced by 20th Century Fox on Wednesday. I shouldn't really have to say anything, just look at the trailer:<br />
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Yes, a Walking with Dinosaurs 3D movie that will be coming out this Christmas. For Dino-Fans like me, this is a <em>godsend.</em> Quite literally this is what the Dinosaur community has been looking for, for ages. I couldn't believe it when I saw it, as it's almost too good to be true. As for why, I'll list the reasons below.<br />
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<ul>
<li><strong><em>Feathered Raptors!!! </em></strong>- If you look at one of the scenes towards the end, their is a sincere feathered Deinonychosaur (It looks to be a Troodon, but I'm not drawing conclusions yet). I have been wanting to see feathered dinosaurs in a movie for so long, and we're finally getting it. It's 100% scientifically accurate, and much better looking than the 6ft bipedal iguanas in Jurassic Park. </li>
<li><strong>Realistic Dinosaurs</strong> - Truly, I have never seen more scientifically accurate looking extinct animals. <a href="http://markwitton-com.blogspot.com/2013/05/the-walking-with-dinosaurs-3d-trailer.html#comment-form">According to Mark Witton on his blog,</a> he as well as other paleontologists and paleoartists like David Krentz, Tomas Holtz, Scott Sampson, Luis Chiappe, and Victoria Arbour have all been involved in re-creating these animals. Heck, according to him they even consulted Mark about the anatomy on the <em>inside of the pterosaur's mouths</em> trying to get every detail as scientifically accurate as possible. I watched over the trailer about a dozen or so times now and I can find only 1 scientific inaccuracy in it (which I will discus below), but seeing as many documentaries fail at even getting that right, this is truly amazing.</li>
<li><strong>Dinosaurs Acting like Dinosaurs</strong> - Unlike Jurassic Park, where the animals are nothing but hideous monsters, or Land Before Time and Disney's Dinosaur, which featured talking, human-like dinosaurs, by the looks of it this appears to be what the title suggests: a 3D movie about Dinosaurs, not human-like or Sci-Fi movie monsters, they act like Dinosaurs. Now, there have been some suggestions in the comments of some of the trailers that these animals will talk, but seeing as they don't talk in the trailer (instead making a lot of animal sounds), it's based on the groundbreaking <strong>documentary</strong> series that goes by the same name, and seeing as the description of the actual movie states that it will be about real-life dinosaurs, I <strong>highly doubt</strong> the animals will talk.</li>
<li><strong><em>Feathered Raptors!!!</em></strong> - Did I mention how amazing this is?</li>
<li><strong>New, Somewhat Unique Story</strong> - The story seems to be following the life of a young <em>Pachyrhinosaurus</em>, born young and weak climbing up to become an alpha male in his herd, and the hardship he faces. At least that's what I got from watching the trailer. However, if you do a little research online it seems that it isn't just following the life, it's a rivalry story. Apparently it doesn't just focus on the main <em>Pachyrhinosaurus</em>, but also on another <em>Pachyrhinosaurus</em>, his brother, and about how they grow up together. I'm guessing that the brother is probably the second little <em>Pachyrhinosaurus</em> slightly larger than our hero in half of the scenes, as well as possibly the other big individual shown during the clash towards the middle of the trailer. This is certainly an interesting concept to put into a Dinosaur movie, especially since every dinosaur movie I've ever really watched seems to be (according to my dad) about getting from Point A to Point B and there are meat-eating theropods in-between. In this movie you're following the life of this individual as well as the hardships he face,s not just with vicious predators and a terrifying world he has to live in, but with his own brother and himself. That's a new and interesting concept that I haven't seen before in a Dinosaur movie, and I can't wait to see how they play it out in the film.</li>
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So as you can see there are a lot of reasons for me to be excited about this movie. It looks simply awesome that they were able to get this many things right, and I can certainly say that I'm now way more excited about this movie than I am about Jurassic Park 4 (which has crushed the hopes of the paleontological community by saying that feathered raptors will not be appearing in the film) and even Pixar's new film <a href="http://en.wikipedia.org/wiki/The_Good_Dinosaur">The Good Dinosaur</a> set to come out next year, which is apparently a cartoony film about a human and his Sauropod friend (that is probably going to talk). The later is an interesting scenario, but not anything I'm really that interested in at 16 years of age.<br />
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However, being the scientist-in-training I am, I am disappointed about a few things. For one, seeing as they got so many things right in this movie, the one glaring inaccuracy out of the entire movie turns out to be our hero himself. Young <em>Pachyrhinosaurus</em> specimens don't show flat faces like the individual in this show. Instead they have a weird growth sequence where juveniles develop a small horn at a young age which later develops into the horn as they mature. This is seriously an <em>extremely</em> minor thing, and in fact I don't even know why I'm bringing it up. I guess it's somewhat disappointing that in a movie where they got everything so right, the fact they missed one thing kind of annoys me.<br />
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I also wish we had feathered Tyrannosaurs, seeing as <em>Yutyrannus</em> was found earlier last year, but according to Witton they designed the Tyrannosaurs before the <em>Yutyrannus</em> discovery came out, so I guess it's acceptable. I also wish the dinosaurs were maybe a little less shrink-wrapped and more speculative, as that's what paleontologists have been trying to push towards nowadays, but again the dinosaurs look great anyways so it's acceptable, and in truth that'd probably be asking for too much.<br />
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After hearing the news about JP4 having featherless raptors and getting <strong>another</strong> new predator appearing, that has definitely lowered my expectations and now I really don't care about the franchise anymore. <strong>This</strong> on the other hand looks spectacular, so I'm pretty dang excited! Can't wait for this to hit theaters! What's everyone else's thought? Feel free to share!Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com6tag:blogger.com,1999:blog-1718421695417441669.post-44549438143584112012013-04-02T21:56:00.000-07:002013-04-02T21:56:33.193-07:00The Plague of the Hesperonychus Meme and its Inaccuracy<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
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<tr><td class="tr-caption" style="text-align: center;"><em><span style="font-size: xx-small;">That darn Hesperonychus meme again! Trust me, there are plenty more where these came from.</span></em><br />
<em><span style="font-size: xx-small;">A random collection of pictures by various paleontologists.</span></em></td></tr>
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I'm not normally one to criticize artwork, but I feel like something needs to be said about this. For those of you who have been keeping up with paleontological blogs (hopefully including mine) you'll remember that <u>All Yesterdays</u> has gotten a lot of praise for pointing out the flaws in modern paleoart, and the memes made by artists who are unfortunately copying other people's work. Darren Naish pointed out some classic memes in his presentations following the publishing of his book, which you can watch <a href="https://www.youtube.com/watch?v=5RG0yLeJE_U&list=PLRdJHg_a89EHEjz9pDiJyOUhlb3-cYXd8&index=3">here</a>, including the "Freaky Giraffoid Barosaurus" and the black and white Phorusrachus memes, both of which have basically become the norm for the two, but I think I found another.</div>
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Those of you who keep up with dinosaur news will remember the discovery of "America's Smallest Meat-Eating Dinosaur" <em>Hesperonychus elizabethae </em>(Currie 2009) (which is technically not true; that title probably belongs to one of our species of Shrike). <em>Hesperonychus</em> was a dromaeosaurid, or more specifically, a member of the subfamily microraptorinae and is the youngest member as well as the first to be discovered outside of Asia. This has made it of particular interest to paleontologists, and has shown that the rather primitive microraptorinae survived close to, if not until the end of the Mesozoic.</div>
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However, what is sad about this wonderful little animal is that ever since its description it has been routinely portrayed as holding its tail almost vertically in the air like a lemur (an image further made iconic by the lemur-like tail stripes on many illustrations), with what look to be relatively short arms, standing on the ground with a mostly brownish coloration. Apparently this original "look" was based on a reconstructed model of <em>Hesperonychus</em> following its publication, and it has since been condemned to this appearance. I know there are certainly more dinosaurs that have been condemned to far worse appearances, but I find this to be not just a pressing problem for<span style="font-size: xx-small;"><span style="font-size: small;"><em> </em><em>Hesperonychus</em> because of the "unoriginality loop" it has fallen into, but it also is being portrayed rather inaccurately.</span></span></div>
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For one, the tail of <em>Hesperonychus</em> has never been found. Indeed, we've only found a partial hip and a few hand bones belonging to the animal, so there is nothing suggesting that it was any different than other microraptorines. Not just that, but you don't see many other raptors holding their tails up in the air, now do you? Might be a fun idea to try, but the majority of fossil evidence currently suggests that microraptorines possessed feathered disks and fronds on their tails. Current research has shown that these tail fronds have an aerodynamic advantage (Habib & al. 2012), and are actually very similar to r<span dir="auto">hamphorhynchid pterosaur </span>tails (Persons & Currie 2012), which is consistent with the idea that microraptorines were gliding animals. However, even terrestrial dromaeosaurids seem to have had such fronds, showing that they likely had an advantage while on the ground as well. The tails seen on the reconstructions of <em>Hesperonychus,</em> however, much more closely resemble those of primitive Coelurosaurs like <em>Sinosauropteryx,</em> and seem totally un-dromaeosaurid-like.</div>
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Given, I know that the tail has not been discovered for this animal, and thus the reconstruction can be based off the artists own personal ideas. But when the reconstruction has been drawn over and over again countless times in the same way with no creativity whatsoever, it gets very annoying. </div>
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And the re-occuring features don't stop there. Often times <em>Hesperonychus</em> tends to be portrayed with what appear to be very short front limbs. This is certainly not always shown; indeed the illustration in the lower right-hand corner in the image above seems to have appropriately-sized arms based on the fossil finger bones and related species, but many of the others just seem to be way too small. The brown coloration has also become routinely shown on this creature, but dinosaur coloration has been shown to have varied widely based on our current melanosome evidence. Again, there is nothing wrong with portraying it as brown, but it's terribly unimaginative after the hundredth time.</div>
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Finally, <em>Hesperonychus</em> is almost never shown with the correct large flight feathers on its forearms that are seen in almost all other dromaeosaurids. This is perhaps due to the original description of the animal, as it was described by Longrich and Currie, who believed that because its size more closely matched that of the large microraptorine <em>Sinornithosaurus millenii</em>, it was probably flightless. <em>Sinornithosaurus</em> has a reduced wing, vaned symmetrical feathers, and seems to be too large to be able to glide, and this was also assumed for <em>Hesperonychus</em>.</div>
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This seems to be a valid argument, but as for why they decided to make their mount completely lack vaned feathers on the arm when they are still present in <em>Sinornithosaurus</em> does not make any sense, and has definitely contributed to the look of the animal. Also, despite Longrich and Currie's conclusion, it is still possible that <em>Hesperonychus</em> was a gliding animal: another dromaeosaurid, <em>Graciliraptor lujiatunensis</em> is in the same size range as both <em>Sinornithosaurus</em> and <em>Hesperonychus</em>, but feather impressions show that it had large, asymmetrical wing feathers and wings that approached similar proportions to the gliding <em>Microraptor</em>, and thus it too may have been able to glide (Martyniuk 2012). This leaves open the possibility that <em>Hesperonychus</em> would've been able to glide as well, and it certainly would be a nice alternative to the illustrations of walking around on the ground like some Cretaceous lemur or something....</div>
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So those are some of my thoughts about this somewhat over-used paleoart meme. Maybe if I'm up to it I'll draw a more realistic <em>Hesperonychus</em> with long arms, large flight feathers, and a horizontally positioned tail climbing through the branches.</div>
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Yeah, I draw. Given, I don't normally draw and I'm definitely not the best at it, but that doesn't stop me from occasionally trying. If I'm sucessful at a pic, I'll make another post to show you guys. If it was a failure, I'll never bring it up again. 'Til then, stay sharp!</div>
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Refferences:</div>
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Habib, M., Hall, J., Hone, D. and Chiappe, L. (2012). Aerodynamics of the tail in Microraptor and the evolution of theropod flight control." 72nd Annual Meeting of the Society of Vertebrate Paleontology, 20 October 2012.</div>
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Longrich, Nicholas R. and Currie, Philip J. <span class="smallV110">A microraptorine (Dinosauria-Dromaeosauridae) from the Late Cretaceous of North America. Proceedings of the National Academy of Sciences of the United States of America, <span class="data_bold">106 (<span class="data_bold">13)</span>, (2009). <span class="data_bold">5002-5007</span> DOI: <span class="data_bold"><a href="http://www.pnas.org/content/106/13/5002.full">10.1073/pnas.0811664106</a></span></span></span></div>
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Martyniuk, Matthew P. A Field Guide to Mesozoic Birds and other Winged Dinosaurs. Vernon, New Jersey: Pan Aves. (2012) </div>
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Persons, W. S. and Currie, P. J. (2012), Dragon Tails: Convergent Caudal Morphology in Winged Archosaurs. Acta Geologica Sinica - English Edition, 86: 1402–1412. doi: <a href="http://onlinelibrary.wiley.com/doi/10.1111/1755-6724.12009/abstract">10.1111/1755-6724.12009</a></div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-19954094078944675042013-03-17T16:25:00.003-07:002013-03-17T22:18:43.932-07:00Dinosaurs on Ice is out!<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://www.wikidino.com/wp-content/uploads/Troodon-Julio-Lacerda-600x400.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="266" src="http://www.wikidino.com/wp-content/uploads/Troodon-Julio-Lacerda-600x400.png" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Brilliant illustration by Julio Lacerda of an Arctic Troodontid</span><br />
<span style="font-size: xx-small;">You can see this stunning image and more on my first published article.</span></td></tr>
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So, as I've said in a number of previous posts, I was asked back in October to write an article for a magazine called <a href="http://ancientplanet.blogspot.com/">AncientPlanet Online Journal</a>, an online magazine which talks about current research concerning archaeological discoveries and our ancient Earth. I'm sincerely happy to announce that after all my hard work, the article has been published! You can now read the full article in Vol. 4 published on March 12th. I would've written earlier, but I just had my wisdom teeth removed and wasn't able to work on a post (and as a result of the surgery, my face currently looks like a pufferfish).<br />
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Now for a little back story. When I was first asked by the editor of the magazine to write the article, I was, quite frankly, dumbfounded to say the least. After starting this blog in December 2011, this was a major step up! In looking over the other articles in the Journal, I could tell that my work would be published alongside some pretty amazing scientists, and I was honored to say the least. So I went for it, and after a few weeks of researching and writing, I came up with a piece that I was proud of. Thank you to the editor, Ioannis Georgopoulous, for having in faith in me to follow through and deliver a solid final product. I was also able to collaborate with young paleoartist Julio Lacerda, who has to be one of the best paleoartists on Deviantart I've ever seen for his stunning reconstructions of dinosaurs and other extinct animals. I asked permission to use some of his artwork in my article, and he happily agreed. Thank you, Julio, for letting me use your incredible art. I'll have to think of a way to properly thank you, but in the meantime, I recommend all of you visit his blog at <a href="http://thecasualpaleoartist.blogspot.com/">The Casual Paleoartist</a>, which shows all of his amazing work.<br />
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So there you have it, my very first published article. Now I have to decide on what to write for my next one. Any ideas? As always, I'll be happy to take suggestions. Until then, stay sharp!Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-31734639510284378462013-03-04T23:09:00.000-08:002013-03-05T06:35:08.835-08:00Why I'm Ptero-fied of Pterosaurs: Giant Pterosaurs and Killer Storks<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://pterosaurs.files.wordpress.com/2008/05/more_azhdarchids_with_clouds1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="486" src="http://pterosaurs.files.wordpress.com/2008/05/more_azhdarchids_with_clouds1.jpg" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">AHHH!!! RUN AWAY!!! HIDE ME!!!</span><br />
<span style="font-size: xx-small;">Image by Mark Witton</span></td></tr>
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Putting aside the horribly awful, facepalm-inducing title as well as the girly screams from your host here at the moment, Pterosaurs are a group of archosaurs related to (but not considered) dinosaurs that lived during the Mesozoic. They were the first vertebrates to develop powered flight, which they developed by evolving an elongated 4th finger and a layer of skin called the <span class="vk_ans vk_dgy">patagia from this finger to the hind limbs, and they just took off from there (no pun intended). In recent years especially, fossils of this family have shown really amazing things about their lifestyles and behavior. We now have fossil eggs showing that unlike many modern-day birds and bats, some pterosaurs may have been able to fly right after birth (Unwin 2005); specimens preserving soft tissue have shown that many pterosaurs had crests made up of soft tissue on their heads for displaying their age, health, and even gender (Lü <em>et al</em>. 2011), as well as being covered in some kind of fuzz termed pycnofiber (<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Proc.+R.+Soc.+B&rft_id=info%3A%2F10.1098%2Frspb.2009.0846&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+soft+tissue+of+Jeholopterus+%28Pterosauria%2C+Anurognathidae%2C+Batrachognathinae%29+and+the+structure+of+the+pterosaur+wing+membrane&rft.issn=&rft.date=2009&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Frspb.royalsocietypublishing.org%2Fcontent%2Fearly%2F2009%2F07%2F31%2Frspb.2009.0846.abstract&rft.au=Alexander+W.+A.+Kellner%2C&rft.au=Xiaolin+Wang%2C&rft.au=Helmut+Tischlinger%2C&rft.au=Diogenes+de+Almeida+Campos%2C&rft.au=David+W.+E.+Hone%2C&rft.au=Xi+Meng&rfe_dat=bpr3.included=1;bpr3.tags=Other%2CPalaeontology">Alexander et al. 2009)</span>. In my opinion though, the most ground-breaking of all is that despite being often portrayed as giant seagulls and pelicans, the majority of species didn't practice this diet. Indeed, we now know of vulture, hawk, bat, stork, and even toucan analogs among the pterosaurs.</span><br />
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<u><strong>Terrifying Terror</strong></u> <u><strong>that is an Azhdarchid</strong></u></div>
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<span class="vk_ans vk_dgy">Seeing as I've given a lot of love to crocs (speaking of which, I'll continue that crocodylomorph series in a bit) and other ambiguous animals from the Mesozoic here, it only seemed like a matter of time before pterosaurs popped up. However, seeing as I am a big <span style="background-color: white;">fan</span> of these animals, it seems ironic that I'm writing a post on how I'm downright scared of them. Given it's not the whole group that I'm afraid of, it's a specific family of them called the azhdarchids.</span><span class="vk_ans vk_dgy"><br /></span><br />
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<tr><td style="text-align: center;"><a href="http://i.dailymail.co.uk/i/pix/2008/05/27/article-0-0165279D00000578-397_233x399.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://i.dailymail.co.uk/i/pix/2008/05/27/article-0-0165279D00000578-397_233x399.jpg" width="186" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">My God, it's eyeing him hungrily.....</span><br />
<span style="font-size: xx-small;">Pic by Mark Witton, and showing him.</span></td></tr>
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<span class="vk_ans vk_dgy">The a<span dir="auto">zhdarchidae</span> is a family of pterosaurs which only appeared near the end of the Cretaceous (although I have heard of some possible early Cretaceous remains) and include the largest of all pterosaurs, such as <em>Hatzegopteryx</em> and the famous <em>Quetzalcoatlus</em>, which could have wings up to 33 ft long, and stand as tall as a giraffe (earlier claims that these animals reached sizes in excess of 40 ft aren't considered valid). These animals, like most pterosaurs were, for a long time, portrayed as skim feeders — skimming along the surface of the water picking up fish as they went. However, most recent work on these animals have shown that they were in fact stork-like in ecology, and were better adapted to ground-feeding than aerial skimming (for a review, see Naish 2010 or follow <a href="http://scienceblogs.com/tetrapodzoology/2008/05/27/terrestrial-stalking-azhdarchids/">this link</a>), and this is the key reason why I personally find these animals rather threatening. Storks and birds with a similar ecological niche today eat just about any small animal they can fit in their mouth, and seeing as <em>Hatzegopteryx</em> and <em>Quetzalcoatlus</em> <span style="background-color: white;">both reached titanic sizes, would that mean we would be on the menu? Most people would probably think that time travelers going back to the Mesozoic would meet dangers mostly from carnivorous theropods, but could these a<span dir="auto">zhdarchids </span>be an equal, if not greater threat? It's an interesting idea, and indeed, it's been <a href="http://pterosaur-net.blogspot.com/2012/04/its-dumb-its-awesome-its-our-lives-with.html">talked at length before by other scientists</a>. But just to see how dangerous they would be, I'm going to look over them a bit and see for myself.</span></span><br />
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<span class="vk_ans vk_dgy">To determine how much of a threat an animal might be to humans, normally there are three factors involved. The first is behavior: is the animal naturally agressive? This is the major determining factor to tell how dangerous many animals are, but since a<span dir="auto">zhdarchids</span> are extinct we can't know this. The other two are easier: numbers and threat. Is the animal common enough that it will come into contact with people often? And what features does it have that can cause damage to us? Knowing this, let's see what a<span dir="auto">zhdarchids</span> bring to the fray:</span><br />
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<span class="vk_ans vk_dgy">As for numbers, we know of numerous giant a<span dir="auto">zhdarchids</span> as of now, and it doesn't seem like <em>Hatzegopteryx</em> and <em>Quetzalcoatlus</em> are alone: two more undescribed giants have been found in the Dinosaur Park and Two Medicine Formation, both of which may reach the same sizes. Thus, there are a lot of species which could hypothetically be a threat, and since the fossil record tends to be rather fragmentary, it is quite possible that there were even more giant pterosaurs out there that are waiting to be found, and indeed, may never be found. Thus, seeing as they are a common animal in their ecosystem, they fill at least the quota for frequent interactions for hypothetical time travelers. But could they actually pose a threat?</span> <br />
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<tr><td style="text-align: center;"><a href="http://fc09.deviantart.net/fs70/f/2012/272/c/1/giant_stork_of_doom_by_fragillimus335-d5gao5i.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="292" src="http://fc09.deviantart.net/fs70/f/2012/272/c/1/giant_stork_of_doom_by_fragillimus335-d5gao5i.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><em>Hatzegopteryx's</em> <span style="color: black;">reconstructed head compared to, believe it or not,</span></span><br />
<span style="color: black;"><span style="font-size: xx-small;"><em>Giganotosaurus'</em>, the theropod with the largest head. Who's scarier again?</span></span><br />
<span style="color: black; font-size: xx-small;">Pic from Deviantart's Dean Hester (<a class="u" href="http://fragillimus335.deviantart.com/">Fragillimus335</a>)</span></td></tr>
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<span class="vk_ans vk_dgy">The answer is, somewhat surprisingly, a most definite yes. They could indeed pose a great threat to us humans. And no, not in that cliche "Pteranodon with teeth flying off with people in its talons" imagery shown in so many old movies; but in a dynamic, cursorial running-down fashion. (Seriously, Pteranodon means "toothless wing," so why do movie makers constantly show it with teeth? It's more comical than scary!) Studies of a<span dir="auto">zhdarchid<span style="background-color: yellow;"><span style="background-color: white;"> proportions have shown that their limbs are actually similar to those of living hooved animals, and that while they might not be able to actually run, they could still move at fairly high speeds over land (Unwin 1997) (Unwin 2005) (Mazin 2003). But what could they do when they actually caught up to us? Again, they're equipped for handling prey our size: the adjacent image shows the reconstructed heads of <em>Hatzegopteryx</em> and <em>Giganotosaurus</em>, currently the theropod with the largest skull. As you can see <em>Hatzegopteryx</em> dwarf's Giganoto's 1.8 meter skull, reaching an astonishing 3 meters long (I'll admit the proportions may be a bit off though; Giganoto's head looks too big). You might think that this is only the case with the skull's length, but that's also not the case; <em>Hatzegopteryx's</em> jaw was an astonishing <em>minimum</em> width of 50cm at the rear (Buffetaut et al. 2003). I, for example, have a shoulder width of about 46cm, <em>Hatzegopter</em><em>yx</em> could easily swallow me whole.</span></span></span></span><br />
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<span class="vk_ans vk_dgy"><span dir="auto">Now, you put all those traits together, and then realize that along with being fast runners, having huge skulls, and being downright gigantic,<em> they could also fly</em>. Despite some scientists saying that some of these huge pterosaurs were in fact too large to fly, most of these conclusions are based off bad assumptions of flight mechanics and scaling (Witton 2010). Thus, what would stop them from just flying into something like a Terra Nova-style compound and eating everyone in sight? The only way time-travelers would be safe would be if they either built large domes (which would cost an immense amount of money) or by residing in caves or underground bunkers, which might produce other problems. Of course, the most cost effective way to avoid all this would just be to shoot them, but I would like to keep such amazing animals away from such a sad fate.</span></span><br />
<span class="vk_ans vk_dgy"><span dir="auto"></span></span><br />
<span class="vk_ans vk_dgy"><span dir="auto">So as you can see, I would personally find these animals to be a far greater threat in any time travel or Jurassic Park-style film than the majority of the dinosaurs that show their faces on-screen. In fact, based on living animals, I would imagine that predatory dinosaurs would spend most of their time sleeping, like living predatory animals, and would've probably only fed once every one or two weeks. A<span dir="auto">zhdarchid<span style="background-color: yellow;"><span style="background-color: white;"></span></span></span>s on the other hand, would've probably been feeding far more frequently on us smaller animals, like living storks and herons, and would be a much more common and frequent threat. Of course, a<span dir="auto">zhdarchids<span style="background-color: yellow;"><span style="background-color: white;"></span></span></span> are long extinct, and us humans have never had to worry about giant, long- necked animals with beaks coming down to snatch us up. Or have we?</span></span><br />
<span class="vk_ans vk_dgy"><span dir="auto"></span></span><br />
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<span class="vk_ans vk_dgy"><span dir="auto"><u><strong>The Dwarf Man vs The Giant Stork</strong></u></span></span></div>
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<span class="vk_ans vk_dgy"><span dir="auto">In 2010, fossils from the Liang Bua cave on the Island of Flores in Indonesia had identified such an example of a relationship. The cave is best known for its assemblages of fossil stegodonts, giant rats, and the dwarf human species <em>Homo floresiensis</em>, who is arguably the most important human species ever found. Discovered in 2003, <em>Homo floresiensis</em>, or the Hobbit Man, was discovered and announced to be the only example of a species of dwarf human, which evolved by the means of island dwarfism. These hobbits were only about a meter at their tallest, and are really interesting in the size of their brain and apparent ability to use tools and produce fire. I won't go into it, as this is not my specialty, but I recommend people check them out even if you're not very interested in human evolution.</span></span></div>
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<tr><td style="text-align: center;"><a href="http://scienceblogs.com/gregladen/wp-content/blogs.dir/472/files/2012/04/i-db5b218fd7852a5ecbf2c5526831304a-ap10121115567_enl.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://scienceblogs.com/gregladen/wp-content/blogs.dir/472/files/2012/04/i-db5b218fd7852a5ecbf2c5526831304a-ap10121115567_enl.jpg" width="255" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">It's not fantasy: man-eating storks in recent times!</span><br />
<span style="font-size: xx-small;">Image by Inge van Noortwijk</span></td></tr>
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<span class="vk_ans vk_dgy"><span dir="auto">Anyway, what do tiny humans have to do with giant killer a<span dir="auto">zhdarchids? As I was saying, in 2010 fossils of a giant bird were uncovered in the same cave. Dubbed</span> <em>Leptoptilos robustus</em>, it was a giant flightless stork and stood a staggering 2 meters tall, or twice as tall as these hobbits. It's a member of the same genus as living marabou storks, but had reduced flight abilities, such as robust bones. It's unknown if they actually were flightless though, since a complete skeleton has yet to be found, but they were definitely losing their flight capabilities. This has been attributed to the fact that Flores 20,000 years ago was devoid of mammalian predators, and thus the stork may have been taking up the same role as they did on mainland continents (Meijer & Due 2010). True, it had to share that role with Komodo Dragons, which lived on the island at the same time. But what does this mean for our little hobbit?</span></span><br />
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<span class="vk_ans vk_dgy"><span dir="auto">Seeing as adult <em>Homo </em><em>floresiensis</em> were still a good 3ft tall, it's safe to say that they were likely off this bird's menu, as its beak was simply too small to manage them. This doesn't exclude children though, and indeed, these storks would've posed a great threat to any baby or even young hobbits on the island, but would the hobbits have fed on these birds? Fossils have shown cut marks on other animals from the island, notably the stegodonts, but according to an interview, cut marks have yet to be found on any of this bird's remains. Still it would be great to actually see a fossil showing predation on one or the other now, wouldn't it?</span></span><br />
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<span class="vk_ans vk_dgy"><span dir="auto">Anyway, a</span></span>s for what you've gotten out of this today? The lesson is, if you're ever stuck between a T-rex and a <em>Quetzalcoatlus, </em>take your chances with the Rex. Stay sharp and see you soon.</div>
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<span class="vk_ans vk_dgy"><strong>References:</strong></span><br />
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<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Proc.+R.+Soc.+B&rft_id=info%3A%2F10.1098%2Frspb.2009.0846&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+soft+tissue+of+Jeholopterus+%28Pterosauria%2C+Anurognathidae%2C+Batrachognathinae%29+and+the+structure+of+the+pterosaur+wing+membrane&rft.issn=&rft.date=2009&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Frspb.royalsocietypublishing.org%2Fcontent%2Fearly%2F2009%2F07%2F31%2Frspb.2009.0846.abstract&rft.au=Alexander+W.+A.+Kellner%2C&rft.au=Xiaolin+Wang%2C&rft.au=Helmut+Tischlinger%2C&rft.au=Diogenes+de+Almeida+Campos%2C&rft.au=David+W.+E.+Hone%2C&rft.au=Xi+Meng&rfe_dat=bpr3.included=1;bpr3.tags=Other%2CPalaeontology">Alexander W. A. Kellner, Xiaolin Wang, Helmut Tischlinger, Diogenes de Almeida Campos,, David W. E. Hone, & Xi Meng (2009). The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane <span style="font-style: italic;">Proc. R. Soc. B</span> : <a href="http://archosaurmusings.wordpress.com/2009/08/05/what-on-earth-are-pycnofibers/10.1098/rspb.2009.0846" rev="review">10.1098/rspb.2009.0846</a></span><br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Proc.+R.+Soc.+B&rft_id=info%3A%2F10.1098%2Frspb.2009.0846&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+soft+tissue+of+Jeholopterus+%28Pterosauria%2C+Anurognathidae%2C+Batrachognathinae%29+and+the+structure+of+the+pterosaur+wing+membrane&rft.issn=&rft.date=2009&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Frspb.royalsocietypublishing.org%2Fcontent%2Fearly%2F2009%2F07%2F31%2Frspb.2009.0846.abstract&rft.au=Alexander+W.+A.+Kellner%2C&rft.au=Xiaolin+Wang%2C&rft.au=Helmut+Tischlinger%2C&rft.au=Diogenes+de+Almeida+Campos%2C&rft.au=David+W.+E.+Hone%2C&rft.au=Xi+Meng&rfe_dat=bpr3.included=1;bpr3.tags=Other%2CPalaeontology"></span><br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Proc.+R.+Soc.+B&rft_id=info%3A%2F10.1098%2Frspb.2009.0846&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+soft+tissue+of+Jeholopterus+%28Pterosauria%2C+Anurognathidae%2C+Batrachognathinae%29+and+the+structure+of+the+pterosaur+wing+membrane&rft.issn=&rft.date=2009&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Frspb.royalsocietypublishing.org%2Fcontent%2Fearly%2F2009%2F07%2F31%2Frspb.2009.0846.abstract&rft.au=Alexander+W.+A.+Kellner%2C&rft.au=Xiaolin+Wang%2C&rft.au=Helmut+Tischlinger%2C&rft.au=Diogenes+de+Almeida+Campos%2C&rft.au=David+W.+E.+Hone%2C&rft.au=Xi+Meng&rfe_dat=bpr3.included=1;bpr3.tags=Other%2CPalaeontology">Buffetaut, E., Grigorescu, D. and Csiki, Z. 2003. Giant azhdarchid pterosaurs from the terminal Cretaceous of Transylvania (western Romania). <em>In:</em> Buffetaut, E. and Mazin, J. M. (eds.) <em>Evolution and Palaeobiology of Pterosaurs</em>, Geological Society Special Publication, <strong>217</strong>, 91-104.</span><br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Proc.+R.+Soc.+B&rft_id=info%3A%2F10.1098%2Frspb.2009.0846&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+soft+tissue+of+Jeholopterus+%28Pterosauria%2C+Anurognathidae%2C+Batrachognathinae%29+and+the+structure+of+the+pterosaur+wing+membrane&rft.issn=&rft.date=2009&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Frspb.royalsocietypublishing.org%2Fcontent%2Fearly%2F2009%2F07%2F31%2Frspb.2009.0846.abstract&rft.au=Alexander+W.+A.+Kellner%2C&rft.au=Xiaolin+Wang%2C&rft.au=Helmut+Tischlinger%2C&rft.au=Diogenes+de+Almeida+Campos%2C&rft.au=David+W.+E.+Hone%2C&rft.au=Xi+Meng&rfe_dat=bpr3.included=1;bpr3.tags=Other%2CPalaeontology"></span><br />
Mazin JM, Billon-Bruyat J, Hantzepergue P, Larauire G (2003) Ichnological evidence for quadrupedal locomotion in pterodactyloid pterosaurs: trackways from the late Jurassic of Crayssac. In: Buffetaut E, Mazin JM, editors. Evolution and Palaeobiology of Pterosaurs, Geological Society Special Publication,. 217. : 283–296. <br />
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Meijer, H. J.M. and Due, R. A. (2010), A <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.2010.00616.x/abstract#" id="_GPLITA_0" in_rurl="http://i.trkjmp.com/click?v=VVM6MzMyOTM6OTc3Om5ldzoyYmJiN2IyZDRhNzBhOWU3Mjk5NGVjNzYxNThlODNkNTp6LTEwNjMtMTQ3MzA6b25saW5lbGlicmFyeS53aWxleS5jb206MzI5Mjg6NDllMjE4ZGUyOWQwOTAyYzIxNzI4YWUyMTgzZjE0NmE" style="text-decoration: underline;" title="Click to Continue > by Browse to Save">new</a> species of giant marabou stork (Aves: Ciconiiformes) from the Pleistocene of Liang Bua, Flores (Indonesia). Zoological Journal of the Linnean Society, 160: 707–724. doi: 10.1111/j.1096-3642.2010.00616.x<br />
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<span class="vk_ans vk_dgy"><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Science+%28New+York%2C+N.Y.%29&rft_id=info%3Apmid%2F21252343&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=An+egg-adult+association%2C+gender%2C+and+reproduction+in+pterosaurs.&rft.issn=0036-8075&rft.date=2011&rft.volume=331&rft.issue=6015&rft.spage=321&rft.epage=4&rft.artnum=&rft.au=L%C3%BC+J&rft.au=Unwin+DM&rft.au=Deeming+DC&rft.au=Jin+X&rft.au=Liu+Y&rft.au=Ji+Q&rfe_dat=bpr3.included=1;bpr3.tags=Biology%2CZoology%2C+Taxonomy%2C+Evolutionary+Biology">Lü J, Unwin DM, Deeming DC, Jin X, Liu Y, & Ji Q (2011). An egg-adult association, gender, and reproduction in pterosaurs. <span style="font-style: italic;">Science (New York, N.Y.), 331</span> (6015), 321-4 PMID: <a href="http://www.ncbi.nlm.nih.gov/pubmed/21252343" rev="review">21252343</a></span></span><br />
<br />
Naish, Darren. Tetrapod Zoology Book One. Great Britain: CFZ Press. (2010)<br />
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Witton MP, Habib MB (2010) On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness. PLoS ONE 5(11): e13982. doi:10.1371/journal.pone.0013982<br />
<br />
Unwin DM (1997) Pterosaur tracks and the terrestrial ability of pterosaurs. Lethaia 29: 373–386.<br />
<br />
<span class="vk_ans vk_dgy">Unwin, D. M. 2005. <em>The Pterosaurs from Deep Time</em>. New York, Pi Press.</span><br />
<span class="vk_ans vk_dgy"><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Science+%28New+York%2C+N.Y.%29&rft_id=info%3Apmid%2F21252343&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=An+egg-adult+association%2C+gender%2C+and+reproduction+in+pterosaurs.&rft.issn=0036-8075&rft.date=2011&rft.volume=331&rft.issue=6015&rft.spage=321&rft.epage=4&rft.artnum=&rft.au=L%C3%BC+J&rft.au=Unwin+DM&rft.au=Deeming+DC&rft.au=Jin+X&rft.au=Liu+Y&rft.au=Ji+Q&rfe_dat=bpr3.included=1;bpr3.tags=Biology%2CZoology%2C+Taxonomy%2C+Evolutionary+Biology"></span></span><br />
Websites:<br />
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Pterosaur.net, It’s dumb, it’s awesome, it’s… Our lives with pterosaurs, part 2, accessed March 3, 2013. <a href="http://pterosaur-net.blogspot.com/2012/04/its-dumb-its-awesome-its-our-lives-with.html">http://pterosaur-net.blogspot.com/2012/04/its-dumb-its-awesome-its-our-lives-with.html</a>Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-6369688168895993362013-02-17T21:01:00.001-08:002013-02-22T22:04:36.563-08:003 Reasons Why Byronosaurus is Awesome<span style="font-family: inherit;"></span><br />
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<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/e/e2/Byronosaurus.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span style="font-family: inherit;"><img border="0" height="269" src="http://upload.wikimedia.org/wikipedia/commons/e/e2/Byronosaurus.jpg" width="320" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><span style="font-family: inherit;"><em>Artist's depiction of Byronosaurus jaffei</em> from Wikipedia,</span></span><br />
<span style="font-family: inherit; font-size: xx-small;">Probably one of my favorite troodontids due to the incredible number of specializations it has.</span></td></tr>
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<span dir="auto"><span style="font-family: inherit;">Deep down, <em>Byronosaurus</em> has always held a special place within my heart. I first learned about this particular animal in 2008 (even though it was discovered in 1993), after looking through an art book titled <em>Feathered Dinosaurs: The Origin of Birds</em>, written and illustrated by John Long and Peter Schouten, with a forward by Luis M. Chiappe. This was probably one of my favorite books of my earlier junior-paleontologist years, and it still pleases me to simply thumb through the wonderfully fantastic illustrations. They are a feast for the eyes!</span></span><br />
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<span dir="auto"><span style="font-family: inherit;">Looking through the book for the first time, I remember coming across this particular creature with its bizarre appearance and interesting anatomy looking back at me with its thin snout, numerous tiny teeth, and huge eyes. Over time, I became fascinated with the animal and I decided to examine it further. Three distinct traits of its anatomy and behavior stood out at me more so than most other dinosaurs. At this point, the only word to define what I think of this beast is simply awesome — and I will explain why.</span></span><br />
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<span dir="auto"><strong><u><span style="font-family: inherit;">Its Quirky Ears</span></u></strong></span></div>
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<tr><td style="text-align: center;"><a href="http://tucsoncitizen.com/wryheat/files/2010/02/Barn-owl-ears-300x206.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span style="font-family: inherit;"><img border="0" src="http://tucsoncitizen.com/wryheat/files/2010/02/Barn-owl-ears-300x206.jpg" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: inherit; font-size: xx-small;">An owl's skull showing the bizarre placement of its ears</span><br />
<span style="font-size: xx-small;"><span style="font-family: inherit;"><em>Byronosaurus</em> had similar ears, if not more bizarre....</span></span></td></tr>
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<span dir="auto"><span style="font-family: inherit;"><em>Byronosaurus'</em> most notable feature is one that is not obviously seen in any illustration of the animal, but you would probably notice it instantly if you were holding a skull of the creature. The ears of <em>Byronosaurus</em> are extremely large, but curiously, they're also asymmetrically aligned on the head, a trait once thought to be exclusive to only one other family of animals, that happen to also be Dinosaurs — owls.</span></span><br />
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<span dir="auto"><span style="font-family: inherit;">Some species of owls have asymmetrical ears in order to enhance their hearing, as it allows a wider area of sounds to enter their ears, as well as allows them to pinpoint the exact location of prey (note that not all species of owls do, however, as some species have perfectly aligned ears). The famous facial disks of many owl species also help channel sound into their ears, as their shape acts like a large satellite dish. Some northern species are quite capable of locating a single lemming in more than a foot of snow simply by listening to its movements from perches, sometimes more than a half-mile away. All in all it's an extremely effective way of locating prey, and I'm surprised that it isn't an anatomical feature more commonly found in animals.</span></span><br />
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<span dir="auto"><span style="font-family: inherit;"><em>Byronosaurus</em> was, I believe, the first troodont to show such a feature, as its skull is one of the most complete of any troodont (according to my research, but please correct me if I'm wrong). Other troodonts also have been shown to possess asymmetrical ears, which suggests that hearing was very important for these animals as a whole, and studies of the braincase show that indeed it was one of their primary senses, maybe even more so than sight. Unlike owls however, <em>Byronosaurus'</em> inner and middle ear has also been shown to be asymmetrical, while owls have it limited to the external surface. Does this mean that <em>Byronosaurus</em> was more sensitive to sounds than owls? Further study is needed before we can tell, but it certainly does suggest that hearing was extremely important for these animals.</span></span></div>
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<span dir="auto"><u><strong><span style="font-family: inherit;">Pinocchio Jaw</span></strong></u></span></div>
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<tr><td style="text-align: center;"><a href="https://ad8d0c4b-a-62cb3a1a-s-sites.googlegroups.com/site/palaeocritti/by-group/dinosauria/deinynochosauria/byronosaurus/Byronosaurus_skull.jpg?attachauth=ANoY7cr55ng0SSWem1otqKb6bn-kYCFkt-x2qrRZrBPD5Ggw7pCMtbD7xKKmBIvjtSIhb2JrgTwUl0jxfU6NLkTnXiU4EEcO11dbOyGdQTx8tGQR26z6dF1GmHnmjpxFNd07hzDPgYEeNb0MLX1iMBpe95xgQq44z-v2nihsYem35SiglIylkHk49nFzhynnUSGZDkdmbli2w21nxs7eh1fNmdpOVNtgD-fCqS-4YTaBow-Af22YxW1B_YLVThP3eO_oCSMv0AA3-Y3h_w3W9TSYB-MSVDMB2hUc6mtg_lrwmMaatLrQLIQ%3D&attredirects=0" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span style="font-family: inherit;"><img border="0" height="142" src="https://ad8d0c4b-a-62cb3a1a-s-sites.googlegroups.com/site/palaeocritti/by-group/dinosauria/deinynochosauria/byronosaurus/Byronosaurus_skull.jpg?attachauth=ANoY7cr55ng0SSWem1otqKb6bn-kYCFkt-x2qrRZrBPD5Ggw7pCMtbD7xKKmBIvjtSIhb2JrgTwUl0jxfU6NLkTnXiU4EEcO11dbOyGdQTx8tGQR26z6dF1GmHnmjpxFNd07hzDPgYEeNb0MLX1iMBpe95xgQq44z-v2nihsYem35SiglIylkHk49nFzhynnUSGZDkdmbli2w21nxs7eh1fNmdpOVNtgD-fCqS-4YTaBow-Af22YxW1B_YLVThP3eO_oCSMv0AA3-Y3h_w3W9TSYB-MSVDMB2hUc6mtg_lrwmMaatLrQLIQ%3D&attredirects=0" width="320" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: inherit; font-size: xx-small;"><em>Photo of the holotype's snout</em></span></td></tr>
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<span dir="auto"><span style="font-family: inherit;">Along with being the first non-strigiforme animal to show an asymmetrical ear, <em>Byronosaurus'</em> well-preserved skull has also shown a very bizarre form of dentition and jaw morphology unlike that of most dinosaurs. Most troodontids are known for having a wide, U-shaped jaw, with blade-like teeth with coarse serrations and a large denticle size. This has lead troodontids, and famously<em> Troodon</em> itself, to be thought of as possible omnivores, as their jaws resemble herbivorous and omnivorous lizards like Iguanas.</span></span><br />
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<span dir="auto"><span style="font-family: inherit;"><em>Byronosaurus'</em> jaw on the other hand, is anything but that of a typical troodont. The jaw is elongated, pointed, depressed, and very narrow, a far cry from the broad, rather deep, U-shaped mouth of other troodonts, and giving <em>Byronosaurus</em> a very-pointy face, making it basically the dinosaur version of Pinocchio. Along with that, <em>Byronosaurus</em> also has very different teeth; they are small, needle-like, lacking serrations, and there are far more of them than in other troodonts. This all points towards a very different method of feeding, but just what was that method?</span></span><br />
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<span dir="auto"><span style="font-family: inherit;">The ears may give us a clue. As I said, owls use their amazing hearing to pinpoint the exact location of hidden prey without even seeing it. <em>Byronosaurus</em> was likely able to do similar things with its ears, and the teeth could be used to grab onto small prey. However, other troodonts have asymmetrical ears and are currently thought to have fed on small prey items in this way, but they don't have <em>Byronosaurus'</em> unique dentition, which seems far more specialized in that regard.</span></span></div>
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<span dir="auto"><span style="font-family: inherit;">A theory was put forth to explain its skull in the <em>Feathered Dinosaurs</em> book I mentioned. The authors noted that the snout and jaw are fairly reminiscent of the African Bat-Eared Fox, which is a very specialized species of canine that feeds on almost an entirely insectivorous diet. The fox's jaw is long and narrow in order to probe into cracks and holes to get at termites, which is its primary food source, and it uses its small, needle-like teeth to cut up the tough exoskeletons of these invertebrates. Interestingly enough, its huge ears are used in pinpointing the exact location of insects crawling among foliage or underground. Do these traits sound familiar? (Vid above showing some Bat-Eared Foxes in action)</span></span></div>
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<span style="font-family: inherit;"><span dir="auto">So perhaps <em>Byronosaurus</em> is a Bat-Eared Fox analogue; but there is another possibility we should explore. The toothy dentition is also similar to that of fish-eating animals like the Indian Gharial and spinosaurid theropods, so perhaps <em>Byronosaurus</em> was a piscivorous troodont. It's notable that some species of owls, like the Balakiston's Fish Owl and Pel's Fishing Owl, as their names suggest, are dedicated piscivores. These owls use their ears to hunt fish at night by listening for disturbances on the surface of the water, so this is also an equally good fit for <em>Byronosaurus'</em> possible diet. </span><span dir="auto">As for which is more likely, I'll leave that for the scientists as well as all of you to decide. (Vid above showing some owls fishing in some artificial ponds)</span></span><br />
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<span dir="auto"><span style="font-family: inherit;"><u><strong>Eggs, Young, and... absence</strong> <strong>in Parenting? (Gasp!)</strong></u></span></span></div>
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As we all know from almost 100 years now of collecting dinosaur eggs, dinosaurs had incredibly varied ways of raising young and making nests. Sauropods abandoned their young, but gave them a good first chance by laying them near volcanic vents; many hadrosaurs constructed large nests and guarded their young in large colonies; and many ceolurosaurs may have been brought up mostly by dad. Given this incredible diversity of breeding habits in dinosaurs, should it be a surprise that we may have found one more?</div>
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In 1994, two very young, juvenile skulls of <em>Byronosaurus</em> were discovered by Mark Norell, which give us a good look at exactly how this weird dinosaur grew up. (Note, however, that they are only tentatively assigned to <em>Byronosaurus. </em>There is an alternative possibility that they belong to the recently discovered Zos Canyon troodontid, which has yet to be described.) The juveniles were extremely young, possibly even embryos, and show extremely large eyes and shortened faces, giving them the "cute" look characteristic of young animals. However, what is interesting is the location where these eggs were found: deep in the heart of a oviraptorid nest, with a ring of oviraptorid eggs surrounding the specimens.</div>
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<span style="background-color: white;">O</span>viraptorid were primarilly herbivorous theropods common in the region at the time. Oviraptorid adults, juveniles, and nests have been well-documented for almost 20 years now, but this is certainly a conundrum. How do you get two juvenile troodontids in the nest of another dinosaur? Theories have gone back and forth for a while about this.</div>
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One explanation is that the adult oviraptorid was feeding on the juveniles and left their remains in the nest. A possibility, but modern birds often try to keep their nests clean of feeding debris, and indeed many species will often carry fecal matter and uneaten scraps off to make the nest less conspicuous to predators. Birds from ostriches to eagles do this regularly, so why the oviraptorid would leave its nest dirty and conspicuous like this would not make much sense. (The video above shows an adult female Robin removing its young's fecal pellets)</div>
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Another possibility is that the juveniles were preying on the unborn oviraptorids. Predators will often feed on eggs of other young, but still, how bold must these juveniles be to want to take on an oviraptorid nest when they are litterally just a few days out of the egg?</div>
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The last possibility, however, really caught my attention. Some have suggested that the juveniles were present in the nest because <em>Byronosaurus</em> was a brood parasite. Brood parasites are animals that benifit by laying their eggs in other animal's nests, and in return have their eggs and young cared for by the "host" parents. Brood parasitism is surprisingly common in birds, evolving independently at least seven times in birds, as well as in a number of reptile and even insect lineages. Most famous of these animals is the <span dir="auto">Common Cuckoo</span> (<span class="binomial"><em>Cuculus canorus</em>), which lays its egg inside another bird's nest. To see this animal in action, David Attenborough has a great documentary on its particular behavior, which you can see <a href="http://www.youtube.com/watch?v=3FEX1XtNbwo">here</a>.</span></div>
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<span class="binomial">While it does seem like we're speculating quite a bit on this topic, there is some evidence to back up this theory. For example, the fact that there are two individuals is evidence in itself. Unlike modern birds, which can only lay one egg at a time, reptiles and dinosaurs lay two eggs at a time. If a female <em>Byronosaurus</em> really did lay its eggs in the oviraptorid nest, then we should expect two young to be present because that is what the female would end up producing. </span></div>
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<span class="binomial" style="font-family: inherit;">If these troodontids really did practice brood parasitism, it would certainly be a major scientific discovery that would tell us a lot about dinosaur breeding behaviors. But of course, would it really be that much of a surprise? After all, as noted above, dinosaurs exibited a number of extremely varied forms of reproduction, and since all dinosaurs were egg-layers, there are a huge number of options available for some species to cheat on their parental duties.</span></div>
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<span class="binomial"><span class="Apple-style-span"><span class="Apple-style-span" style="font-family: inherit;">So there you have it: </span><span class="Apple-style-span" style="font-family: inherit;"><i>Byronosaurus jaffei</i>,</span><span class="Apple-style-span" style="font-family: inherit;"> t</span></span><span class="Apple-style-span" style="font-family: inherit;">he as</span><span class="Apple-style-span" style="font-family: inherit;">symetrical, pinocchio-nosed, insect-eating, fish-catching, parental cheating son-of-a-gun dinosaur. I hope this has been an informative post, and as you all probably know by now, I'm open to taking questions of all kinds.</span></span><br />
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<span class="binomial" style="font-family: inherit;">Also, for those who are interested..the next edition of <a href="http://ancientplanet.blogspot.com/">AncientPlanet Online Journal</a> should be coming out very soon. I don't have a date, but my article will be appearing in it along with numerous other articles submitted by paleontologists, academicians, scientists, grad students and the like. You can also expect a blog post here covering everything I went over, as well as possibly some stuff that was scrapped at the last minute. ;)</span><br />
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<span class="binomial" style="font-family: inherit;">Meanwhile, stay sharp, and I'll see you on the net!</span></div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-47684030724956030382013-02-09T07:32:00.002-08:002013-02-09T07:32:18.365-08:00Giant DromaeosauridsSo, during my short a absence (partially due to testing at school, partially due to an illness I've had) I've been cooped up and unable to work on some of the blog posts I've started. Yesterday, I decided to make another video, this time devoted to four species of giant dromaeosaurids: <em>Utahraptor ostrummayosorum</em>,<em> Achillobator giganticus</em>,<em> Austroraptor cabazai</em>, and <em>Itemirus medullaris.</em><br />
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<em>Itemirus medullaris</em>, is <em>extremely</em> poorly known, despite the fact it was found in the 50's, which is unfortunate because it seems to represent a huge species of velociraptorinae, making it a first. I was also going to note the huge dromaeosaurid teeth found in England as well as a few fragmentary remains that might belong to dromaeosaurids, but since they all haven't been named or properly described yet, we're just going to have to stick with these guys for the time being.<br />
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Expect more deinonychosaurs soon, and remember that I take requests for post topics. I might even make a video if someone really requests it. :)Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-10098709129141508132013-01-22T20:47:00.002-08:002013-01-22T20:47:23.227-08:00All Yesterdays TributeSo for the few of you that have either been living under a rock, or simply not been in touch with the paleontological community lately (hopefully the majority of you are the latter), Paleoart has taken a major turn for the better with the the publishing of <a href="http://www.irregularbooks.co/"><em>All Yesterdays: Unique and Speculative views of Dinosaurs and Other Prehistoric Animals</em></a>. Authored by Paleoartists John Conway and C. M. Kosemen and Paleontologist/Zoologist Darren Naish, this book has caused so much of an impact that its been compared with Bakker's famous <span id="btAsinTitle"><em><u>The Dinosaur Heresies</u></em>, one of the greatest published milestones in paleontological history</span>. Thus, I thought it may be appropriate to create a tribute to such an amazing book, and I did:<br />
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I know its not anything special, just something I basically threw together during my long weekend, but it is a beginning point for me. I'm hoping to make more videos and put them on <a href="http://www.youtube.com/user/RaptorX863?feature=mhee">my YouTube channel</a> to address more important paleontological discoveries, issues, and debates in the near future.<br />
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Until then, I'm going to do one of 3 things; study dinosaur lactation (yes, a study came out the other day talking about this), research terrestrial island crocodiles, or sleep. Most likely the last option though....Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-69630605698227562952012-12-31T10:05:00.000-08:002012-12-31T14:59:37.300-08:00Dino (and Mammal)-Eating Crocs Part 3: The First Neosuchians<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
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<em><span style="font-size: xx-small;">*Before I start, I must apologize for misusing the term Crocodilian in my last post concerning these animals. Crocodilian is used to define all the members of the Crocodilia, which include living crocodiles and all their closest extinc relatives, and not the Notosuchian + Neosuchian branch Metasuchia. Instead, the more broad term in considered to be Crocodylomorph, which is what I will use in this post.</span></em></div>
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<a href="http://upload.wikimedia.org/wikipedia/commons/5/58/Stomatosuchus2.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="212" src="http://upload.wikimedia.org/wikipedia/commons/5/58/Stomatosuchus2.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Image of <em>Stomatosuchus inermis</em>, a large Crocodylomorph from mid Cretaceous Africa.</span><br />
<span style="font-size: xx-small;">Its toothless lower jaw and possibly pelican-like throat pouch are just one example of diversity in the Neosuchia.</span></td></tr>
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As I had shown in the previous post concerning Notosuchians, during the Mesozoic all kinds of these reptiles were running around under the feet of dinosaurs, and in some cases, directly competed with them for resources, territory, and living space. However, the other group of Crocodilimorphs, known as the Neosuchia, were just as, if not more diverse as their Neosuchid brethren, and exploited another type of environment; the water. Such a high level of diversity should really be expanded longer than a single blog post, but in an effort to save time, I'll be just quickly scanning though a few of the various groups and families.<br />
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The earliest known Neosuchian, called <em>Calsoyasuchus valliceps</em>, dates back to the early Jurassic, and predates the Neosuchia by almost 90 million years. However, despite being so old, <em>Calsoyasuchus</em> is a fairly derived form of Crocodilimorph, being a member of the Goniopholididae family, and suggests the Neosuchia originated even earlier. Goniopholididae were the first group of semi-aquatic Neosuchians, and would've resembled modern crocodilians in many ways. However, they lacked many defining characteristics, such as a well-developed secondary palate which allows them to breath while their body is submerged, and would've probably needed to lift most of their head out of the water to get a gulp of air.<br />
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More primitive Neosuchians only occur later in the fossil record. The <span dir="auto">Atoposauridae are often thought to be the most primitive family within the Neosuchia, but they don't appear until the late Jurassic, leaving another 30 million year gap between them and <em>Calsoyasuchus</em>. They seem to have been primarily land-living animals that resembled armored monitor lizards, and were probably filling a similar niche to them in the shadows of dinosaurs. As time went on, however, this certainly did change. W</span><span dir="auto">hile both the Goniopholididae and the <span dir="auto">Atoposauridae represent the earliest offshoots to the group, the second offshoot, however, has been getting more press with the discovery of <span dir="auto"><em>Dakosaurus</em>; the <span dir="auto">Thalattosuchia, or sea-crocodiles. </span></span></span></span><br />
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Image showing just a few species of <span dir="auto">Metriorhynchids with a diver for scale. </span></span><br />
<span style="font-size: xx-small;"><span dir="auto"></span></span><span style="font-size: xx-small;"><span dir="auto">Despite the </span></span><span style="font-size: xx-small;"><span dir="auto">image portraying </span></span><span style="font-size: xx-small;"><span dir="auto">a 4.5m <em>Dakotosaurus</em>, s</span></span><span style="font-size: xx-small;"><span dir="auto">ome species may have rivaled </span></span><br />
<span style="font-size: xx-small;"><span dir="auto"><em>Plesiosuchus</em> in size.</span></span></td></tr>
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">The Thalattosuchia</span> are as far as we know the only crocodilians adapted towards a fully pelagic existence. They evolved during the mid Jurassic and persisted into early Cretaceous times, and are separated into two families; the very crocodilian-like <span dir="auto">Teleosauridae and the very fish and whale-like <span dir="auto">Metriorhynchidae. The <span dir="auto">Teleosauridae have elongated jaws, and are thought to have been primarily shallow water piscivores, although some members like <span dir="auto"><em>Machimosaurus</em> have their teeth regularly found embedded within turtle shells. They show numerous adaptations for diving, however, such as big neck muscles and short, compact bodies, but still hold onto the elongated crocodile-like tail of their ancestors. The <span dir="auto">Metriorhynchidae were much more whale-like in appearance as well as feeding methods, sporting killer whale-like teeth, and many having shorter porpoise-like snouts. These were presumably the toothed whales of the age, and being equipped with well-developed salt glands, fish-like tails, and flippers, they lived a fully aquatic existence. They are also currently believed to be the only members of the Archosauria to be ovoviviparous, in that they likely held onto the young in the body and gave live birth to them.</span></span></span></span></span></span></span></span></span><br />
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">However, despite often being considered members of the Neosuchia, some recent cladistic analysis of these animals have suggested that they may be more primitive, perhaps even outside of the Metasuchian branch altogether, and thus I shouldn't be including them in this post. For a more in-depth review of this as well as any information you may want to know about these creatures, see <a href="http://blogs.scientificamerican.com/tetrapod-zoology/2012/10/09/awesome-sea-going-crocodyliforms-of-mesozoic/">Darren Naish's recent article concerning these animals.</a></span></span></span></span></span></span></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"></span></span></span></span></span></span></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">Next are possibly one of my favorite families among the primitive members of the Neosuchian branch, the <span dir="auto">Mahajangasuchidae</span><span dir="auto">. So far the family has only been identified by two species, both from Africa, <em>Mahajangasuchus</em> <em>insignis</em> from Madagascar and <span dir="auto"><em>Kaprosuchus saharicus</em> from the Sahara. They are characterized by their short and deep jaws, horn-like projections over the eyes, and fused nasal bones, the latter trait they share with the tyrannosauridae. They also both show adaptations in their skulls that suggest a largely if not fully terrestrial existence, such as more laterally positioned forward-facing eyes. In the case of <span dir="auto"><em>Kaprosuchus</em>, it had six pairs of elongated teeth and an armored nose, which may have allowed the animal to kill large, land-based prey.</span></span></span></span></span></span></span></span></span></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"></span></span></span></span></span></span></span></span></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><em>Kaprosuchus</em> has been getting some attention ever since its discovery, and has been portrayed on National Geographic's special When Crocs Ate Dinosaurs, as well as the British television series Primeval. </span></span></span></span></span></span></span></span></span></span></span><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">Despite not really realizing it, <span dir="auto"><em>Mahajangasuchus</em> has gotten some screen time as well. In the 2005 remake of King Kong by Peter Jackson, they portrayed in a short scene a crocodile-like creature chasing after the lead heroine Ann Darrow before getting eaten by a T-rex-like animal. The creature was later confirmed in a "Natural History Book" about Skull Island to be known as<em> </em>Foetodon ferrus, but looking over its anatomy, its overall build and size shows an uncanny resemblance to <span dir="auto"><em>Mahajangasuchus</em>, and I wouldn't be surprised if it was based on the latter.</span></span></span></span></span></span></span></span></span></span></span><br />
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Image comparing the giant extinct </span><span dir="auto"><span style="font-size: xx-small;">Pholidosaurid <em>Sarcosuchus</em> to a living crocodile.</span></span><br />
<span dir="auto"><span style="font-size: xx-small;">Their has been a debate as to what <em>Sarcosuchus</em> was eating; mostly land-based dinosaurs,</span></span><br />
<span dir="auto"><span style="font-size: xx-small;"> or mostly fish. </span></span><span dir="auto"><span style="font-size: xx-small;">I personally find the later more likely. Sorry Sarco fans...</span></span></td></tr>
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The Tethysuchia are a group of crocodilians which evolved near the end of the Jurassic, and survived into the Paleogene epoch. Within this group their are two families, the <span dir="auto">Pholidosauridae and Dyrosauridae. The Pholidosauridae, which includes <span dir="auto"><em>Pholidosaurus,</em> <span dir="auto"><em><i>Meridiosaurus</i></em>, and the infamous <strong>"Super Croc"</strong> <span dir="auto"><em>Sarcosuchus</em>, which was one of the largest<span style="font-size: xx-small;"><span style="font-size: small;"> </span><span style="font-size: small;">Crocodylomorph</span> </span>to have ever existed. They were primarily long-jawed predators of fish with widened, bulbous noses, but some</span> species of bucked this long-jaw trend entirely; <em>Oceanosuchus </em>had jaws similar to a modern day Alligator. The Philosauridae went extinct about 90 million years ago, likely after suffering heavy losses after the Cretaceous Thermal Maximum (CTM).</span></span></span><br />
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The Dyrosauridae were similar to the Pholidosauridae in many aspects, and are their sister group, but came about 20 million years later in geological time. They appeared about 70 million years ago and survived the K/T event that wiped out the dinosaurs. Most had, like the Pholidosauridae, elongated jaws with numerous teeth, suggesting again, a mainly piscivorous lifestyle, though some species, such as <em>Phosphatosaurus</em>, had more traditional crocodilian-like teeth and jaws. This group survived up until their extinction in the Eocene, likely being victims of another small extinction event hat occurred at this time, although their disappearance could also be explained by competition withthe more advanced crocodilians.<br />
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Next come quite possibly, in my opinion, the most extreme members of any Crocodylomorph lineage. The Stomatosuchidae were a small family, like the Mahajangasuchidae, and have only two currently accepted genera. The first discovered was <em>Stomatosuchus</em>, which was unearthed by Ernst Stromer during one of his expeditions to Egypt, but was sadly lost along with the original <em>Spinosaurus</em> and <em>Carcharodontosaurus</em> remains during WW2. The second was <em>Laganosuchus</em>, which was described and discovered by Paul Sereno in 2009.<br />
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The original remains of <em>Stomatosuchus</em> were not very complete, but it suggested that the animal was over 30ft in length. <em>Laganosuchus </em>was probably smaller, reaching a little over 20ft. The upper jaw had tiny teeth, but the lower jaw may have been toothless (although <em>Laganosuchus</em> has small teeth in it's lower jaw). While Sereno has suggested that these animals may have been ambush predators, waiting jaws open for something to swim into them, I'm sceptical of this. The wideness of the jaws would produce a lot of drag in water, preventing them from being closed effectively at high speeds. Any rapid movement of such wide jaws would've also produced currents that would alert the fish of the danger through it's lateral lines, if not carry the fish out of their jaws entirely.<br />
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I instead believe that, since their jaws show similarities to living whales, these animals may have been hunting fish through filter-feeding. Perhaps they actively followed after schools of fish, swallowing them in gigantic mouth fulls. It would've certainly been a niche that they could fit into nicely, seeing as the only other creatures hunting like this at the time were gigantic fish in the family pachycormidae, and even these huge fish were likely feeding on tiny plankton rather than other fish species. So it seems the stomatosuchidae had this unique lifestyle and feeding habits to keep all to themselves. (although another Crocodylomorph family, the aegyptosuchidae, may have been doing similar things)<br />
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So their we go. I know it is a bit short, but I told everyone I'd try to get this done before the end of the month, and I was running out of time.<br />
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Still, I'm not done yet, and I'd really like to get into some more crocodilians next time, including more modern crocodilians that are all scattered across the past. I've also been facinated by a species of land-living (if not arboreal) crocodilan that may have crossed paths with early Homo sapiens, and you can be sure it will be talked about sooner or later. ;)Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com1tag:blogger.com,1999:blog-1718421695417441669.post-48984508580037164842012-12-24T16:42:00.000-08:002012-12-24T16:42:02.769-08:00Happy Holidays!Hey everyone! Just making this quick little post to wish you all a Happy Holidays and great New Year. The next crocodilymorph post is almost done, although I may have to separate it into two parts since the Neosuchia is such a vast family to cover. Other than that, I'm hoping I'll be able to post some more things on here for the next few weeks before school starts again. I'm also working on some other post (if you haven't realized it yet, I just right about whatever I'm looking into at the present time) and hope they'll be done before school starts next year.<br />
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Anyways, as I said before, I wish you all a very Happy Holidays and hope to see you all soon....Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-39727414163237708522012-12-22T18:11:00.001-08:002013-03-18T16:04:07.954-07:00Anatomy and Paleobiology of Spinosaurid Dinosaurs<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Illustration by Brian Engh depicting two <em>Spinosaurus aegyptiacus</em> doing what their family does best:</span><br />
<span style="font-size: xx-small;">fishing, and swimming.</span></td></tr>
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<span dir="auto">Recently, I have been speaking with a number of people online concerning the life habitats and paleobiology of the spinosaurid dinosaurs, which is a family of highly specialized theropods that had evolved aquatic habits and are known to eat fish. The information we've been discussing has certainly inspired me to do a post on these animals, and they're one of my personal favorites among theropods due to their bizarre appearance and specialized behaviors.</span></div>
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Spinosaurids were a family of dinosaurs within the megalosauroid radiation of tetanuran theropods which seem to have evolved during the late Jurassic. W<span dir="auto">hile original spinosaurids remain limited their range to North Africa, South America, and Europe in predominantly swampy and tropical paleoenvironments, the last five years has revealed remains from every continent (excluding Antarctica, although I bet we'll eventually find them there). <a href="http://link.springer.com/article/10.1007%2Fs00114-012-0911-7">An ungual phalanx from the famed Morrison formation is also thought to be from <span style="background-color: white;">one of these animals</span></a>, and <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3353904/">a neck vertebrae from Australia has been found to come from a juvenile spinosaurid</a>. The latter is from the same locality that we're currently finding a number of polar dinosaur species, proving that these animals weren't limited to swampy environments.</span></div>
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<span dir="auto">Combinations of stomach contents, shed teeth, and even embedded bones from prey within the jaws of these animals prove that they were piscivores, and fed on a diet of fish. <a href="http://geology.gsapubs.org/content/38/2/139.abstract">A study of oxygen isotope levels in spinosaurid teeth have also shown that they were indeed spending the majority of their time submerged within water</a>, and perhaps actively swimming after fish in their underwater world. However, the discovery of bones from a sub-adult <em>Iguanodon</em> within the European <em>Baryonyx</em> specimen, along with a pterosaur vertebrae with part of a spinosaur tooth embedded within it prove that despite their fishy diets, they were still capable of feeding on land-based prey. The fact they were aquatic may also suggest that some of these theropods were feeding on marine reptiles like plesiosaurs and icthyosaurs. We have found marine reptile bones and teeth in some of the same deposits, but this is all speculative until any evidence is found that they preyed upon these animals.</span></div>
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<strong><u>Body Builders of the Mesozoic?</u></strong></div>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><em>Image of armature paleontologist William Walker with the thumb claw of</em> <em>Baryonyx walkeri</em><em> in his hand.</em></span><br />
<em><span style="font-size: xx-small;">The individual Baryonyx who left this claw was about 9 meters long, and it was not even fully grown!</span></em></td></tr>
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A common trait seen in many, if not all members of the spinosauridae is their well-developed arms. Despite many people claiming that these animals had long arms, they aren't particularly long compared to other theropods, the obvious exceptions being tyrannosaurs and alvaresaurids among others. Instead they are well-muscled and very robustly built. The lower arm bones are relatively short, but the humerus length makes up for it. The fingers show a high degree of flexibility like many big theropods, and the thumb was tipped with an extremely large thumb claw.</div>
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Many have suggested that these arms were used for fishing, rather like how a bear will use its forelimbs to catch salmon. However, similar robust arms are also seen in earlier Megalosauroids, so perhaps their use was the same throughout the group. Megalosaurs are thought to have used their robust arms to help with dispatching large land-based prey animals, and we know currently that Spinosaurids at least occasionally fed on dinosaurs, so perhaps their arms were used to kill them as well. Still, they would have also served very effective for fishing when the time came.</div>
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<strong><u>Billboards, Fish Traps, or Giant Humps?</u></strong></div>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Skeletal reconstruction by Scott Hartman showing the full extent of some <i>Spinosaurus</i> vertebral spines</span><br />
<span style="font-size: xx-small;">Wonder if I could advertise my blog on one of those things....</span></td></tr>
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<span dir="auto">The most noticeable part of any spinosaur must be the elongated dorsal neural spine along their backs, producing a "sail" or ridge along the backbone. In some species these became very elaborate: <em>Spinosaurus</em> itself has neural spines which were over five feet tall, and <span dir="auto"><em>Ichthyovenator </em>had not one, but two sails along its back.</span></span></div>
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<span dir="auto"><span dir="auto">The evolution and purpose of these sails has been at the center of a hot debate. Some scientists think that they may have served a thermoregulatory function. Many of these creatures were living in some of the hottest environments the Mesozoic had to offer, and these vertebrae could serve as extra surface areas to cool down the animal during the hottest parts of the day. However, if the animals were really spending a lot of time submerged in water, this may not have been a problem for them, as the water would keep them cool. </span></span><span dir="auto"><span dir="auto">The sails may also have served as visual display organs. Similar structures are found in other dinosaurs and living animals, and may have served as billboards to advertise to other animals their age, size, gender, species, and overall health. The sheer number of sail shapes and forms found within the group supports the idea they were for some form of visual communication, and I agree that that is likely one of their functions.</span></span></div>
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Another theory I have heard be suggested is the fishing lure idea. Some living birds like herons use their wings to shade the water around them, which attracts fish to the animals where they can then be easily snatched up in their bill. Some have suggested the same thing was happening with spinosaurids, using their sails to shade the water and attract fish, but I personally find myself disagreeing. Many species have low ridges that could not serve such a function, and the sails are thought to appear as an offset to sexual maturity, further suggesting the visual idea.</div>
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<span dir="auto"><span dir="auto">Stromer had his own idea for the sail, however. He suggested that the sail may have supported a hump-like structure filled with muscles. While originally dismissed for the sail-backed animal, Jack Bailey resurrected the hypothesis in 1997, and reconstructed what looked like a giant terrestrial crocodile with a bison-like hump on its back (similar to the extinct archosaur <em>Arizonasaurus)</em>. However, this posture and reconstruction now seems, at best, unlikely, but the hump theory still isn't out of the question. As both he and Stromer noted, the sail is made up of thick and strong vertebral extensions, a far cry from the thin extensions in some sail-backed animals, like <em>Dimetrodon</em>, but very similar to the thicker extensions in living hump-backed animals, like bison and camels.</span></span></div>
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Living bison use these muscular humps on their backs to power huge neck muscles for both plowing through snow and head-butting mates during the breeding season. Camels use their humps to store fat (NOT water) while traveling over large desert landscapes. Bears also have muscular humps over their shoulders to power huge arm muscles while hunting, digging, and moving large objects (in some cases even boulders weighing over a ton), but how would the spinosauridae possibly use such a structure?</div>
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<a href="http://theropoda.blogspot.com/2009/01/spinosaurid-paleobiology-more-than-just.html">Investigation into the neck vertebrae in spinosaurids suggests that, while they had rather weak side-to-side motion in the neck, they had well-developed muscles responsible for the up-down motions.</a> Such a fast up-down motion might be good when catching fish and raising them out of the water while swimming, and any muscles in this sail may have assisted them while hunting. The well-developed arms of spinosaurs may also have been powered by muscles that extend into these structures, although as I mentioned about megalosaurs, they would have still been powerful without them.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzpOslqAc7IV9TGmDvfYvHznBfr1Tqko3pXwh7ixGW6vgz6TL6x5ykzTHVdbtC2e4ckaMyaB22cDLFRNaZAmw2aiBL99l6qsF1gI8vlFZR1OfG-Zp3aL98kERvZe98MD_712K8WY8WVBk/s400/Spinosaurus+skull.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhzpOslqAc7IV9TGmDvfYvHznBfr1Tqko3pXwh7ixGW6vgz6TL6x5ykzTHVdbtC2e4ckaMyaB22cDLFRNaZAmw2aiBL99l6qsF1gI8vlFZR1OfG-Zp3aL98kERvZe98MD_712K8WY8WVBk/s200/Spinosaurus+skull.jpg" width="195" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">One of the best and most used skull reconstructions of <em>Spinosaurus</em> I've seen on the net, with the rear proportions based off its relative <em>Irratator</em>.</span><br />
<span style="font-size: xx-small;"> The image is from Andrea Cau's Theropoda blog, although I don't know the exact origins of it (except it's modified by S. Maganuco).</span></td></tr>
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Leaving their vertebrae, we of course come to their next most defining feature in spinosaurids: their heads. The skulls of spinosaurs were all low and elongated, similar to a crocodile, and due to their fishy diets it's no wonder why. However, despite this general shape, the skulls between different species can differ dramatically between the two subfamilies; the <strong>Baryonychinae</strong> and the<strong> Spinosaurinae</strong>.</div>
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The skulls of members of the baryonychinae are known for their moderately raised nostrils, rounded eye socket, numerous closely-spaced teeth, shallow lower jaw, and extremely small, but numerous serrations on the teeth. These animals include <em>Baryonyx walkeri</em> and <em>Suchosaurus cultridens</em> from Europe (although the latter may be dubious), the African <span dir="auto"><em>Suchomimus tenerensis</em>, possibly <em>Ostafrikasaurus crassiserratus </em>(if it's not more primitive<em>),</em> and</span> <span dir="auto"><em>Cristatusaurus lapparenti</em> (again, the latter may be dubious), the Asian <em>Ichthyovenator laosensis</em>, and presumably the newly discovered Australian specimen, Morrison specimen, and a Campanian tooth from China all belong to members of the the baryonychinae.</span></div>
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The defining skull features members of the spinosaurinae share is their extremely high nostrils (half way up the skull), raised teardrop-shaped eye sockets, widely-spaced and relatively longer teeth, deeper lower jaw, and lack of serrations. These members so far include the African <em>Spinosaurus aegyptiacus</em>, the South American <em>Irritator challengeri</em>, the extremely fragmentary <em>Oxalaia quilombensis</em>, and possibly <em>Siamosaurus suteethorni</em> (since its teeth closely resemble those of <em>Spinosaurus</em>).</div>
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Both groups have raised nostrils, which helps them to breathe while submerged. In the spinosaurinae they are especially high up, which allows them to still breathe in deeper water, and the eyes are also partially raised, allowing them to also see while submerged. This could possibly indicate that the spinosaurinae were more aquatic than the <span style="background-color: white;">baryonychinae, and the large sizes of some members of the spinosaurinae (both <em>Spinosaurus</em> and <span dir="auto"><em>Oxalaia</em> could get larger than <em>Tyrannosaurus</em>)</span> may have been supported by the weightlessness of this lifestyle.</span></div>
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The differences in jaw morphology may also reflect different lifestyles among the two groups, most notably spaces between their teeth. The teeth of the <span style="background-color: white;">baryonychinae were uniformly-spaced, while the teeth of the spinosaurinae had spaces which varied. The former arrangement is more similar to living fish-eating gharials, which have interlocking teeth to allow them to more successfully catch small slippery fish. However, the latter spinosaurinae have an arrangement that is more similar to other types of crocodilians, and might suggest that like them, their diet was more varied. Alternatively, varied spaces between teeth are also seen in crocodilians which feed on larger prey, so it is also possible that the spinosaurinae were feeding on larger prey items than the baryonychinae.</span></div>
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Comparisons between the skulls of different types of spinosaurids have been going on for a while now. <a href="http://www.bioone.org/doi/abs/10.1671/0272-4634%282002%29022%5B0766%3ATEHITS%5D2.0.CO%3B2?journalCode=vrpa">Donald M. Henderson started it off in 2002 when he examined <em>Suchomimus'</em>s skull and found that it was weaker in comparison to the skulls of the much smaller dinosaurs like <em>Dromeosaurus.</em></a> This was due to the skull's weaker build compared to other theropods, which have taller skulls in order to counter-act stresses while biting. <a href="http://www.academia.edu/286991/Functional_Morphology_of_Spinosaur_Crocodile-MimicDinosaurs">In 2007 Emily Rayfield made similar findings in the closely related <em>Baryonyx walkeri</em></a>. However, <a href="http://theropoda.blogspot.com/2009/01/spinosaurid-paleobiology-more-than-just.html">paleontologist Andrea Cau posted on his blog Theropoda about the skull of <em>Spinosaurus</em></a> as well as members of the spinosaurinae, and suggested that unlike the <span style="background-color: white;">baryonychinae</span>, it may have had a much stronger bite.</div>
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He noted numerous adaptations in the skull which could be responsible for a more powerful bite force, and I quote:</div>
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<em><span style="font-size: x-small;"><span style="background-color: white;">"How powerful was that bite? A precise quantification is not possible, however, it should be noted that increasing the length of the rostrum, increases the moment of the force exerted by the muscles mandibular end of the rostrum. The long skull of a Spinosaurus was adapted to withstand the forces exerted by its own bite? The cross section of the rostrum, triangular, the presence of the long nasal dorsal ridge which served as a point of discharge of the forces and the presence of the long secondary palate (a mechanical expedient to resist torsion), all adaptations are intended to support the intense stresses caused bites very powerful. A further indication of this capability is given, at least in Spinosaurus, from the retracted position of the nostrils: this odd fact that the entire region was placed in front of the nostrils consists of only compact bone, with no cavities or soft part, and then allowed to exercise precisely at the level of the rostrum of the considerable pressures without the risk of damaging vital parts such as the nostril."</span></span></em></div>
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This suggested to me that unlike members of the baryonychinae, the spinosaurinae were better adapted to feeding on a range of animals from fish, to pterosaurs, to dinosaurs with their more powerful bites. However, while writing this article <a href="http://www.academia.edu/1812192/Structural_performance_of_tetanuran_theropod_skulls_with_emphasis_on_the_Megalosauridae_Spinosauridae_and_Carcharodontosauridae">I came across yet another paper concerning the strengths in spinosaur skulls published in 2011 (again by Emily Rayfield)<span style="background-color: white;">.</span></a> This study was similar to the <em>Baryonyx</em> one in that she digitalized the skulls of 7 different theropod species, including <em>Suchomimus</em> and <em>Spinosaurus</em>, and put them under stress in a 3D computer program to see which ones were most effective at distributing it. The results were surprising.</div>
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Ou<span style="font-family: inherit;">t of all the dinosaurs in the study, the three largest theropods, <em>Acrocanthosaurus</em>, <em>Carcharodontosaurus</em>, and <em>Spinosaurus</em> had the highest levels of stress in the skull. <em>Spinosaurus</em> especially showed levels off the main curve, and was likely unable to feed on larger dinosaurs, being restricted to smaller prey. Ironically, this study found that despite Henderson's stating that the skull of <em>Suchomimus</em> was incredibly weak, this study found that it was in fact just as good at distributing stresses as the other theropods graphed, and the skull was overall much stronger than Henderson thought.</span></div>
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<span style="font-family: inherit;">I am, however, reluctant to make these seem like conclusions since Emily <span style="background-color: yellow;"><span style="background-color: white; color: black;">he</span></span><span style="background-color: white;"><span style="color: black;">rself</span><span style="color: white;"> </span></span>stated that they could not be 100% sure that the <span style="color: #231f20;">results were accurate based on the resources she had. She instead suggested that the study should be considered more of an educated prediction, and should be test<span class="l7">ed with the offset of better 3D models in the future</span>. I personally can't wait until such advances are made and we can more accurately find out how these skulls worked, and thus learn how these creatures behaved.</span></span></div>
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<strong><u>Why, what big teeth you have!</u></strong></div>
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<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;">Image of the jaw of <em>Baryonyx</em> from <span class="a" style="left: 708px; top: 1248px;">Emily J. Rayfield's paper reguarding its skull</span></span><br />
<span style="font-size: xx-small;"><span class="a" style="left: 708px; top: 1248px;">As you can clearly see from image B, spinosaurid teeth were extremely long.</span></span></td></tr>
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But of course, one of the most interesting things I'd like to get into is these animal's teeth. The teeth of all spinosaurs show some of the greatest examples of convergence within the theropods, greatly resembling crocodilian teeth to the point that we have trouble telling isolated examples of the two apart. Both croc and spinosaurid teeth are nearly conical in shape and appearance, but in the <span style="background-color: white;">baryonychinae, these teeth still held onto serrations along the front and back like other theropods, but are so small that they can only be seen with a microscope. The spinosaurinae teeth have become truly conical and have no serrations present, but also tend to be thicker as well as larger than <span style="background-color: white;">baryonychinae teeth</span>. <a href="http://www.academia.edu/1300482/Fine_sculptures_on_a_tooth_of_Spinosaurus_Dinosauria_Theropoda_from_Morocco">Both groups also show large amounts of wear on their teeth.</a> Similar wear is seen in crocodilians, marine reptiles, as well as some toothed whales, further evidence that these were aquatic animals.</span></div>
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<a href="http://www.scielo.br/pdf/aabc/v83n1/v83n1a06.pdf"><em>Oxalaia</em> is also unique from all other theropods in one regard.</a> The tooth in the third row has shown not one replacement tooth behind the functioning one, but two. This is unusual as replacement teeth tend to grow one at a time in most theropods. For those that don't know, both dinosaurs and crocodiles replace their teeth by resorbing the existing tooth at its base to make room for the replacement. The replacement eventually moves to a position within the functional tooth, and when resorption is largely complete, the existing tooth falls away, allowing the new tooth to take its place.</div>
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The fact that <em>Oxalaia</em> has two replacement teeth within one socket means that it would've been resorbing and producing two teeth at the same time within one another, almost like Russian nesting dolls. Due to the fact we only have one extremely fragmentary <em>Oxalaia</em> specimen, we can't tell if this was a "freak" individual or a trait the species had as a whole, but it certainly shows these animals were weird in their own ways. However, I haven't even gotten to one of the most significant things about these teeth in my opinion: their sheer size.</div>
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Many people just don't realize that how big spinosaurid teeth were. At first glance the teeth of spinosaurids may seem about the same size as those of other theropods, despite their odd shape. But CAT scans of the skull have shown that their roots were extremely deep, sometimes embedded half-way within the socket. Similarly deep roots are also seen in, again, crocodilains, but in <em>Spinosaurus</em> itself these teeth may have been over 10 inches long, rivaling T-rex's banana-sized 12 inch teeth for the longest theropod tooth! It has surprised me just how little documentation exists about the size of spinosaurid teeth, and very few people I've talked to know how long they actually are. Many scientists have referenced the length of these teeth in the past, such as Thomas Holtz, <a href="http://www.youtube.com/watch?v=vu8Ve-3N2Ho">who has talked about their length in the documentary Monsters Resurrected</a> as well as <a href="http://www.enchantedlearning.com/dinotalk/holtzbrettsurman/questions/17sam.shtml">while answering questions online</a>.</div>
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So that's it. Thanks to everyone who I've been talking to about these fascinating creatures, and hopefully talking about these crocodile mimics will get me back in the mood to write about actual crocs....</div>
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Eh-hem....</div>
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As always, feel free to ask any questions you may have. But to make it seem a bit more exciting around here, you get extra points if you understand the Holtz reference. Until next time, stay sharp and see ya around the net. ;)</div>
Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com2tag:blogger.com,1999:blog-1718421695417441669.post-80209502258955862122012-12-04T21:31:00.003-08:002012-12-05T17:09:38.108-08:00Digging on the Net: Birds of ParadiseA few weeks ago, I found myself walking down my driveway after a long day of school. I turned to my left and saw the mail had come in, so I decided to grab it and save my parents some trouble. However, I noticed I got a new edition of National Geographic magazine in the mail, and one of the sections listed on the cover said something about the Birds of Paradise, scientifically known as the Paradisaeidae, and are best known for their spectacular and diverse plumage in males. I entered my house, dropped all my things on the way up to my room, and quickly indulged into the world of these spectacular and diverse birds.<br />
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It turned out that after 8 years of looking and studying Birds of Paradise, photographer Tim Laman and Cornell University ornithologist Ed Scholes were able to be able to document and photograph every living member of the family, including the never-before photographed and rarely ever witnessed Buff-Tailed Sicklebill. Their discoveries and footage include never-before seen views of these animals, and completely unexpected realizations about their mating behaviors. I wasn't going to make a post about this, but a recent <span class="qualified-channel-title"><a href="https://www.youtube.com/show/nationalgeographiclive">National Geographic Live!</a> </span>interview has given me a good chance to show you all just how spectacular these creatures are:<br />
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I know there's been a lot of bird-related things on this blog recently, but expect it, since birds are the living representatives of Dinosaurs, and in my opinion, we should be basing Dinosaur behavior off them. In my opinion, if a bird practices some type of behavior, then Dinosaurs probably would've done similar, of not the same behavior. And yes, that includes the possibility that male T-rex were dancing around, clearing areas on forest floors in order to make them seem sexier to females of their species.<br />
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<em><span style="font-size: x-small;">Yes, I know, I'm working on the Neosuchian post. I'm just stuck on this one part and currently looking for the information to refresh my memory on it. It'll be within the month, but expect some shorter posts in the meantime.</span> </em>Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com2tag:blogger.com,1999:blog-1718421695417441669.post-9478567571854733292012-11-22T12:54:00.004-08:002012-11-22T12:54:27.078-08:00Happy Thanksgiving<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://images.fineartamerica.com/images-medium/turkey-strutting-james-jones.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="196" src="http://images.fineartamerica.com/images-medium/turkey-strutting-james-jones.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><em>Two male Wild Turkeys performing their characteristic "strutting" behavior.</em></td></tr>
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For this quick post, I'd like to say Happy Thanksgiving to all my American followers here, and talk briefly about one of America's National emblems, the Wild Turkey<em> (</em><span class="binomial"><em><strong>Meleagris gallopavo</strong></em>)</span>. Often taken for granted by us humans, and often described as very dumb birds, Wild Turkeys are greatly misunderstood animals, which encourages me to devote a few paragraphs here to discussing them on what should be considered their own national holiday.<br />
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The Turkey is the largest living member of the Galliformes, or gamebirds, a group of about 290 species of mostly terrestrial birds that have compact bodies, small heads, short beaks, and high-wing loadings. Galliforme young are precocial, which means that they are able to walk within hours of birth, and in the case of Megapodes (large gamebirds from Australia and surrounding areas of land) their young are superprecocial, and are able to fly within their first day out of the egg.<br />
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Gamebirds as a whole are a very successful group; they've colonized every continent except Antarctica, and are found everywhere from tropical rain forests to frozen tundra. They are well known for often showing extreme forms of sexual dimorphism, and males are often larger than females and have almost excessive amounts of display plumage, which reaches its most extreme in peacocks and some pheasants. In some species of gamebird, males have an enlarged spur on their hind feet that can be used in both territorial battles, and as a defense against predators. (I think that a similar function might have encouraged the evolution of enlarged claws in dromeosaurids, iguanodontians, and prosauropods, although I doubt sauropods used their thumb claws in this way, since they seem more likely to have been used in foraging, according to recent studies.)<br />
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<tr><td class="tr-caption" style="text-align: center;"><em>Male Turkey displaying coloration of </em><br />
<em>his head and waddles</em></td></tr>
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Turkeys in particular are very interesting gamebirds if you've seen them before. I've seen them myself on a few occasions, and they look and act like very proud animals. The males even have a behavior called "strutting" where they walk around displaying to both females and other males while dragging their wings, puffing up their tail and chest feathers, and pulling in their head. During this behavior, males have been known to change the color of their head based on how they're feeling, similar to what cassowaries and chameleons do, with blue heads signaling excitement, and red heads signaling aggression. They can also engorge the skin and waddles around their head with blood, causing them to swell up almost to the point where the eyes and beak are concealed.<br />
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The bare, blood-filled skin and thick body feathers in males doesn't come without consequences. Some studies has shown that overheating is a problem at times, and males will often rest in the shade for hours at a time, and have been known to pant on hot days like dogs and crocodiles do. Females, with less body plumage and more plumage on the head when compared to males, don't have as much of a problem, and are free to forage for food most of the day without resting. The diet of a Turkey includes grain, leaves (including conifer needles), nuts, seeds, berries, roots and insects. They have also been observed eating small vertebrates, including frogs, lizards, and even snakes.<br />
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<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/e/e7/Wild_turkey_and_juveniles.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/e/e7/Wild_turkey_and_juveniles.jpg" width="162" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><em>Female Turkey with Chicks</em></td></tr>
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As with almost all gamebirds, males play no role in parental care, and are <span dir="auto">polygamous, mating with multiple females in a season. The female is thus left entirely responsible for taking care of the offspring, which can sometimes be up to 14 juveniles. The eggs are layed about one day apart in a shallow dirt impression, and they all hatch after about 28 days and leave the nest within their first 24 hours. The female will then watch over the young for the next 8-10 months until they are large enough to take care of themselves.</span><span dir="auto"> If confronted by a predator, turkeys prefer to run rather than fly, using their long, athletic legs to escape danger, although if forced to they have been known to be quite agile fliers, and will sometimes roost in trees to sleep in relative safety.</span><br />
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<span dir="auto">Native Americans have long relied on turkeys, and they were considered a vital food source for many eastern tribes. During the first Thanksgiving, the governor of Plymouth sent out four men to catch turkeys for the big feast, and came back with enough turkeys to last them a week. However, turkeys weren't the only animals being served. Deer, geese, ducks, swans, passenger pigeon, fish, eels, shellfish, mussels, clams, and lobster were also on the menu. After the first Thanksgiving, British trading ships brought the animals back to Europe as food. They were forced to travel through Constantinople in Turkey before reaching other countries. People then associated the birds with that nation, which is where their name comes from.</span><br />
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<span dir="auto">Sadly, it seems that food is one of the only things Turkeys are remembered for in history, but one famous historical figure thought highly of Turkeys. <span class="mw-headline" id="Benjamin_Franklin_and_the_national_bird_suggestion">Benjamin Franklin wanted the Turkey to be the national bird of the United States rather than the Bald Eagle. He believed the Turkey to be a more noble and proud bird than the Bald Eagle, as he had witnessed Bald Eagles stealing food from other smaller birds, and basically bullying them into submission (many Raptors are known do this). Many disagreed with him, however, preferring the stronger and more powerful Bald Eagle over what they viewed as the comical turkey. I'm happy with the Bald Eagle as America's national bird, but I'm also glad that Franklin looked past the non-traditional beauty of the Turkey and saw an attractive and proud creature behind that plump body.</span></span><br />
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<span dir="auto"><span class="mw-headline">I wish you all a Happy Thanksgiving, and hope you will respect the animal who gave their life for your meal today. As for me, I'm a vegetarian, so I'll be staying away from these birds today and hope those that did not end up on your plates will get fed just as well as I will today. What will I eat if not Turkey, you ask? Cauliflower bisque, herb-crusted tofu with mushroom gravy, chestnut sage stuffing, cranberry sauce, green bean casserole, candied yams, and delicious pumpkin pie are all on the menu tonight. Whatever is on your menu tonight, enjoy the holiday with your family and friends! And expect a lot of posts next month, since I'm going to be off for the Holidays.</span></span>Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-56381327691809305382012-11-16T21:56:00.002-08:002012-11-16T21:56:26.547-08:00OH MY GERSH! Where's RaptorX?<div class="separator" style="clear: both; text-align: center;">
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIfPnnz07_qIwwl-75Py6zA27xUkkG5PeBs9Pc02u6DOUpK7A-QOdDIUhBrN1tPAFH_C7ObgMwfklf6Nbn0ztUHIFsNE8BpKmOLdCD-0b3AjD_omvwWDmDxJwJHE3h12zGnW9V6496MUfA/s1600/994866%5B1%5D.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIfPnnz07_qIwwl-75Py6zA27xUkkG5PeBs9Pc02u6DOUpK7A-QOdDIUhBrN1tPAFH_C7ObgMwfklf6Nbn0ztUHIFsNE8BpKmOLdCD-0b3AjD_omvwWDmDxJwJHE3h12zGnW9V6496MUfA/s320/994866%5B1%5D.jpg" width="210" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A Common Potoo having a panic attack.</td></tr>
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Hey everyone, bet you were all expecting a Croc post last week. Sadly I haven't been able to get on it yet, I've been busy working on some other things, some of which I'd like to tell you all about.<br />
The first news is that I'm writing an article for a new online magazine, called <a href="http://ancientplanet.blogspot.com/">AncientPlanet Online Journal</a>. The magazine looks nice and I''m excited that some of my articles will be appearing in it. It's every two months though and I'm trying to balance out getting info for the articles, and getting my school work done. I also have a <a href="https://www.youtube.com/user/RaptorX863?feature=mhee">YouTube account</a> now if anyone is interested in talking to me on there. I might also start making videos, but I'm not sure yet, as it'll make me even more busy than I am now.<br />
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As for Crocs, it might be a while before I get to writing that post. In the meantime you might want to go over to Darren Naish's blog <a href="http://blogs.scientificamerican.com/tetrapod-zoology/">Tetrapod Zoology</a>. He recently wrote a few articles on Neosuchid crocodiles, and even though I know a lot about these things, I still probably can't explain them the same way an actual scientist can.<br />
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As for the meme, it's made by yours truly. The image is of a Common Potoo, which is a type of nocturnal bird from South America related to nightjars, swifts, and hummingbirds. It's an insect eater and uses its enormous mouth to gulp down moths and other insects in flight, and is famous for its amazing camouflage capabilities, being able to mimic a broken tree stump almost perfectly. It also is known for the strange call it emits, which sounds almost like a human saying "poor me, all alone." Here's some less comical images of Potoos:<br />
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<tr><td style="text-align: center;"><a href="http://www.billhubick.com/images/common_potoo_cr_200703_02.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="213" src="http://www.billhubick.com/images/common_potoo_cr_200703_02.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Head profile of a Common Potoo. The huge mouth has tiny bristles inside which help trap any insects that get caught.</td></tr>
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<tr><td style="text-align: center;"><a href="http://www.surfbirds.com/media/gallery_photos/20090301084436.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://www.surfbirds.com/media/gallery_photos/20090301084436.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">This Common Potoo was curious of the camera when this photo was taken. A Potoo's large yellow eyes are used to help them see in the dark, but give them somewhat of a bug-eyed look.</td></tr>
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<tr><td style="text-align: center;"><a href="http://www.oiseaux.net/photos/olivier.paris/images/ibijau.gris.olpa.1g.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://www.oiseaux.net/photos/olivier.paris/images/ibijau.gris.olpa.1g.jpg" width="213" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Common Potoo hiding in plain site. It might not seem wise to close its eyes when hiding from predators, but Potoos have small notches in their eyelid which allow them to see even when their eyes are closed.</td></tr>
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<tr><td style="text-align: center;"><a href="http://farm3.static.flickr.com/2631/4195589831_936ff20a57.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://farm3.static.flickr.com/2631/4195589831_936ff20a57.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Common Potoo showing its young the art of hiding. Potoos and their relatives have such good camouflage that they can fledge chicks directly on a bear tree branch, and sometimes even open ground without ever being spotted by a predator.</td></tr>
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Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0tag:blogger.com,1999:blog-1718421695417441669.post-91659642701413805042012-10-28T21:23:00.000-07:002012-11-02T09:50:55.401-07:00Dino-Eating Crocs Part 2: Success of the Notosuchia<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://images1.wikia.nocookie.net/__cb20120808025920/dinosaurs/images/e/e3/Baurusuchus.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="235" src="http://images1.wikia.nocookie.net/__cb20120808025920/dinosaurs/images/e/e3/Baurusuchus.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><em><span style="font-size: xx-small;">A depiction of Baurusuchus eating a turtle. T</span><span style="font-size: xx-small;">hese crocodilians were taking up the roles of</span><span style="font-size: xx-small;"> Dinosaurs near the</span><span style="font-size: xx-small;"> end of the Cretaceous, and were proving to be deadly adversaries.</span></em></td></tr>
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When you think of the paleoecology of the Cretaceous period, normally you think of dinosaurs filling up all the niches available, as this period was the height of their success. But this couldn't be further from the truth. During the Cretaceous, many forms of animals took up the intermediate roles between the folds of nature, and while some think these areas were ruled by mammals, that's actually not the case either. It seems that these niches were mostly filled by a group of crocodiles, known as the Notosuchia.<br />
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The Notosuchia are a well known group to scientists. We first found their bones more than a hundred years ago, but they remain mysterious and unknown to the public. Their fossils have been unearthed in South America, Africa, Europe, and even as far as East Asia. They were fully terrestrial, as shown by their un-flattened tails, level nostrils and eyes, and long legs, and ranged in size and shape from small little animals no larger than a housecat, to fairly large animals that could've given theropods a run for their livelihood. Their strange teeth and dietary preferences have made them famous in the paleontological world.<br />
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The best description of their teeth is that they're mammal-like, although they really have no close resemblance to any animal living or extinct, and were probably more competitive with mammals than dinosaurs ever were, as they occupied the same niches. Some even seem to have given up a diet of meat and evolved towards herbivory, such as <span dir="auto"><em>Chimaerasuchus</em> from China and <span dir="auto"><em>Malawisuchus </em>from Malawi. Others were opportunistic omnivores, such as <span dir="auto"><em>Notosuchus</em> from Brazil and <em>Araripesuchus</em> from all over the Southern Hemisphere. The latter's genus also lasted from 125 - 65 mya, meaning it survived for more than 60 million years, longer than most other land vertebrates from the Mesozoic and certainly longer than any dinosaur genus I know of.</span></span></span><br />
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<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/c/ce/Chimaerasuchus_paradoxus.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://upload.wikimedia.org/wikipedia/commons/c/ce/Chimaerasuchus_paradoxus.jpg" width="286" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><span dir="auto"><em>Chimaerasuchus, a 6ft herbivorous croc from Early Cretaceous China.</em></span></span><br />
<span style="font-size: xx-small;"><span dir="auto"><em>The location where this fossil was found is the farthest</em></span></span><br />
<span class="Apple-style-span" style="font-size: xx-small;"><em>the group ever got from the Equator.</em></span></td></tr>
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<span dir="auto"><span dir="auto"><span dir="auto">There were many bizarre members of the Notosuchia, but it's interesting to note that many resemble living mammals. <em>Armadillosuchus</em> has probably the most prominent name of the group, resembling a living Armadillo, and having armor carapaces along its back for defense. <span dir="auto"><em><span dir="auto"><i>Mariliasuchus</i></span></em> looked profoundly like a gopher or other burrowing mammal, and has actually been found lying within possible burrows along with associated eggs. <em>Notosuchus</em> had fleshy lips, and might have had either a hog-like snout, or possibly even a trunk like a tapir. Some looked like cats, such as <span dir="auto"><em>Pakasuchus</em>, which has large eyes and a similar body form to modern felines.Their were even alien-looking animals like <span dir="auto"><em>Yacarerani, </em>which had a bizarre dentition that looked a lot like a rat or other rodent. All these similarities with mammals, along with the fact that they had upright legs and likely exhibited active lifestyles, has suggested to some researchers that these crocodilians were endothermic, but an examination of this idea has yet to be performed.</span></span></span></span></span></span><br />
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These animals were definitely filling up mammal niches, and it's probably due to this group, not the dinosaurs, that most mammals in the Southern Hemisphere stayed small. However, in many places that these small crocs roamed, we're now finding that herbivorous dinosaurs were absent, suggesting that they were also taking up dinosaur roles in the environment. Take South America for example, almost all kinds of hypsolophodont from the northern side of the continent were gone by the Late Cretaceous, but in their place we found these little animals scurrying around. The same is also true of Late Cretaceous Madagascar, we've yet to find one Ornithopod or Ceratopsian in the environment, their niches completely filled with crocs instead. The occurrence of <span dir="auto"><em>Chimaerasuchus</em> in China also roughly coincides with the disappearance of many small ornithopods in that region. However, the disappearance of <span dir="auto"><em>Chimaerasuchus</em></span> also roughly coincides with the diversification of many plant-eating theropods, possibly meaning that once these crocs left the region, theropods filled the niches that both groups had held previously.</span><br />
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<span dir="auto">The most competitive, and probably my favorite members of the group were the s<span dir="auto">ebecosuchia, which occupied not the niches of small ornithopods and mammals, but were predators taking up the roles that small- to mid-sized theropods had. Along with the mammal-like teeth of other members of the Notosuchia, members of the sebecosuchia also evolved theropod-like teeth, and in some members like <em><span dir="auto"><i>Stratiotosuchus</i></span></em>, canine-like teeth evolved. They evolved stiff backbones and longer legs, better for actively running after prey, and resembled giant reptilian dogs. These were also the largest members of the Notosuchia, with some species reaching about 15-20ft.</span></span><br />
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I imagine these animals to be ambush predators, lying in wait along game trails, waiting for an unsuspecting dinosaur to wander by, and possibly even pursuing the animal for a short distance at high speeds until they tired. This behavior, along with their ecological niche, would've put them right at the same level as large theropods, and would've been just as dangerous to the local herbivore populations. In many fossil sites around the world, these animals seem to have even replaced <span dir="auto">theropods </span>as the top predators as time went on.<br />
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<tr><td style="text-align: center;"><a href="http://www.wired.com/images_blogs/wiredscience/2012/01/dino-croc-660x404.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="195" src="http://www.wired.com/images_blogs/wiredscience/2012/01/dino-croc-660x404.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"><em>A Stratiosuchus preying on some kind of Titanosaur.</em></span><br />
<span style="font-size: xx-small;"><em>Image by Maurílio Oliveira.</em></span></td></tr>
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This is most strikingly the case in a formation called the <span dir="auto">Adamantina Formation, which is a layer of rock in Brazil that dates back from 90-83mya. This could be called the Lost Land of the Crocodiles, and the entire fauna is dominated by these animals, with more than 15 species present and virtually no dinosaurs or mammals represented. Instead of mid-sized theropods we see <span dir="auto"><em>Baurusuchus</em>, <span dir="auto"><em>Campinasuchus,</em> and <span dir="auto"><em>Stratiotosuchus</em> filling these roles; in place of ornithomimids and oviraptors, we instead have pig-like animals like <span dir="auto"><em>Armadillosuchus</em> and <span dir="auto"><em>Mariliasuchus; </em>and in place of ornithopods and mammals, we have a whole dynasty of herbivorous species present in the fossil layers. The only dinosaurs present are Sauropods, which seem to have been the only dinosaur group these animals couldn't match in ecological role. However, I've recently heard of some unidentified theropod material that's come from the formation, and a fossil Barusuchid apparently has some theropod bite marks preserved on its bones, which might indicate that these dinosaurs were present. But still, the majority of animals in the formation were Notosuchids, and it seems that they took control of this specific region. Why exactly? We may never know.</span></span></span></span></span></span><br />
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<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">At the end of the Cretaceous, after all the major dinosaur faunas went extinct, leaving only birds and mammals to take their roles, these crocs didn't go back into the water to join their Neosuchid kin. In fact, the discovery of numerous members of the s<span dir="auto">ebecidae found in Cenozoic rocks proves that these animals survived the disaster at the end of the Cretaceous, and were still as big, powerful, and competitive as ever, and ready to try and take up the roles as predators of mammals. In South America scientists have found the s<span dir="auto">ebecids <span dir="auto"><em>Sebecus</em>,</span> <span dir="auto"><span dir="auto"><span dir="auto"><em>Bretesuchus</em>, <span dir="auto"><span dir="auto"><em>Langstonia,</em> and<em> </em><span dir="auto"><em>Lorosuchus</em> in the same fossil rocks as members of the <span dir="auto">Phorusrhacidae and <span dir="auto">Sparassodonta, which we believed for a long time were the only large predators on the continent. Not just that, but <span dir="auto"><span dir="auto"><em>Bergisuchus</em> from Germany and <span dir="auto"><em>Eremosuchus</em> from Algeria also shows that they survived in places outside of South America.</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br />
<span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto"><span dir="auto">Seeing how the group was comprised of large, active, possibly even warm-blooded predators, how did they survive the K-T extinction event? Well, apparently one articulated <i><span style="font-family: CharterITCBT,Italic; font-size: x-small;"><span style="font-family: CharterITCBT,Italic; font-size: x-small;"><span style="font-size: small;">Baurusuchus</span></span></span></i> specimen suggests the possibility that even these large animals dug burrows, possibly in order to hibernate during tough times as seen in modern day Nile Crocodiles. This behavior could have helped them survive the extinction 65mya that wiped out the dinosaurs, and allowed them to live on through the Cenozoic. But then, why aren't they around nowadays?</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br />
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There are many mysteries surrounding the extinction of the Notosuchids, however the extinction does coincide with a sharp decrease in global temperatures, known as the <strong>m</strong><span dir="auto"><strong>id-Miocene disruption</strong>, which might have spelled doom for a group of crocs without any form of insulation to keep them warm</span>. Still, these animals must have been magnificent to see in their glory, and it certainly proves that crocs were definitely not lying down on their lazy bellies by the water's edge during much of their evolution. They were active, powerful, and quite capable of giving even the "Terrible Lizards" a good run when they were alive.<br />
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There we go, part one of the Crocs done, and I'll be posting part two within a few weeks, so I'll see you all then!Tristan Stockhttp://www.blogger.com/profile/08416626700060143529noreply@blogger.com0