Goodbye 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.

As such, I've decided that I shall be making a move to a separate blogging location. My new blog, titled Notions of a Most Peculiar Dinosaur Nerd, 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.

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! :)

My Opinions on the NOVA Spinosaurus Documentary.

So, I just finished watching the new Spinosaurus documentary on PBS titled "Bigger than T. rex". 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:

My thoughts on the NOVA Spinosaurus documentary:

-Saw an ad for the museum I work at prior to the start of the show. Tis a good sign.
-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?
-Typical promising NOVA opening. Draws you in and gets you in the mood quickly.
-CAMELS!!! I love Camels.
-Peter Dodson's comparison of Spinosaurus to Nessie immediately brought this to mind: http://thewoodparable.deviantart.com/art/Nessie-a-derived-spinosaurid-482581711
-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...
-The typical NOVA animations and reenactment scenes really fit the mood. Just my personal opinion.
-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.
-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.
-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?
-Just wanted everyone to know, I called this predators in Kem Kem ate fish thing first: https://www.youtube.com/watch?v=JuYo5-YuAoM
-Me: Please explain your methods!
*Never explains methods.*
Me: Dammit...
-Stop saying birds are dinosaur's "closest living relatives". Just say they ARE dinosaurs! It makes us museum interpreters' lives so much easier.
-Bubba is the most calm Alligator I've ever seen. I want to hug him.
-I still don't think everyone agrees the sail looked like that, but, whatever...
-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?
-Again, not everyone agrees with the quadrupedal thing, but, whatever...
-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.
-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!
-"Spinosaurus makes sense." Tell that to all the scientists who are still scratching their heads while waiting for the monograph!
-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!

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.

Now, if you excuse me, I'm going to be waiting quietly in the corner for the Spinosaurus monograph we've been promised. Cheers!

Short legs are in?

Spinosaurus aegypticus discusses with a certain individual of Homo sapiens about movie star traits.

So, everyone that's been keeping up with the Spinosaurus stuff these past few weeks have probably seen this post by Mark Witton by now. In it, Ibrahim and co. consulted with Mark and checked over the proportions and scaling in his model, which Mark checked a few days prior and found similar results to Scott Hartman's own numbers. 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 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.

So, what does this mean?

Spinosaurus' comically short legs are real.

And my thoughts?

...AWESOME!!!

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.

Now, however, we should get onto the important bits about what the new legs actually mean. Spinosaurus 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 Spinosaurus, since unlike those people, I don't care what Spinosaurus as an animal looked like. However I do care about why it looks that way, and that's where the biological questions of this new model come in.

So, how's a short-legged Spinosaurus 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 Headden's post 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.

Pangolin waddling along... Waddle, waddle...

Moreover, as many people who've read about this already know, tail length in dinosaurs is highly varied, even on the individual level, and it's likely that many dinosaurs may have under-sized and/or over-sized tail proportions. Spinosaurus' 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 Spinosaurus even more while walking.

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.

Behold the Crococormorant! Art by yoult of Deviantart, and name proposed by ornithischophilia.

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 Spinosaurus a real-life Godzilla?

I'll leave you all with a third and possibly my favorite proposed method of locomotion for Spinosaurus. Stay sharp everyone! Cheers!

Obviously this method of locomotion proposed by Osmatar perfectly explains all of the bizarre proportions to the new Spinosaurus

Spinosaurus is back!

So, if you’re a paleo-nerd like me, you’ve probably read all about the new Spinosaurus material announced by 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^th 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.

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 Science, Nizar Ibrahim and Paul Sereno published their long-anticipated paper on Spinosaurus material recovered from Morocco and other parts of the Sahara, and the material doesn’t just conclude that Spinosaurus was the longest theropod dinosaur, but it also reveals it has anatomy which was, well, bizarre:

OMG! What have they done to you Spiny!?

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 Spinosaurus 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 Spinosaurus, 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…

“No T.rex, please don’t take my fish and try to make me reach for it…”

- Probably no Spinosaurus aegyptiacus ever. I mean seriously, Spino and T.rex never met. I'm sure all the bullying came from the Carcharodontosaurus.

I do find it interesting that spinosaurids have been suggested as quadrupeds so many times in literature. There have been mentions of Spinosaurus as a quadruped since (I believe) the 70s, and the discovery of Baryonyx further promoted this idea with its incredibly robust forearms. Furthermore, the idea of a quadrupedal theropod isn’t impossible. 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 Spinosaurus the first? I wouldn’t count on it.

The proposed evidence that 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 Spinosaurus’ 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. (See Jaime Headden’s post to understand why this still doesn’t work.) 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. Cau pointed out earlier today why a chimeric origin is very unlikely, but it doesn’t matter, as this limb shortness might all be untrue anyways.

Spiny! You're, well, still kinda short...

Scott Hartman was quick to point out on his blog that the skeletal given doesn’t appear to match the measurements provided by the authors in their own paper. When corrected, Spinosaurus 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 Spinosaurus 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 BEFORE major broadcasting stations latch onto them and turn them into major money-making exhibits and documentaries. (Predator X and Darwinius anyone?)

(Interestingly, the CGI Spinosaurus 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…)

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.

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.

What’s also weird in my opinion is the vertebral column. It’s pretty long, and in fact gives Spinosaurus a swan-like neck and dachshund-like body. It is actually kind of similar to the distantly related theropod Majungasaurus, 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 Spinosaurus 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.

Er, wait… So is Spinosaurus 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 Spinosaurus 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.

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^th 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 Cau and Headden 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.

Yummy, yummy, fishy, fishy...

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 Spinosaurus 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? Thescelosaurus? CMN 8547? Lurdusaurus? Opisthocoelicaudia? Heck, and what about other spinosaurids? Did everyone forget about this paper?

Also, since Irritator and Oxalaia are close relatives to Spinosaurus, shouldn’t we regard them as having similar anatomy as well? Both of them are only known from skull material, and as Michael Mortimer showed, two caudals from the Alcantara Formation of Brazil were classified as Sigilmassasaurus. Since Sigilmassasaurus was just now found to be synonymous with Spinosaurus and spinosaurid in nature, it’s likely that they belong to Oxalaia. 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 Spinosaurus was part of a much larger subfamily of semi-aquatic theropods which we’ve yet to discover?

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.

As always, I’d love to hear suggestions for future topics. I’m also now on Facebook and Deviantart, 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!

SVP LA

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.

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 Deinocheirus, and the possible resurrection of the genus Brontosaurus. 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.

New look for Deinocheirus
The neck, ridge, and legs all based on new info from SVP.

Wednesday, Oct. 30: 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 Chasmosaurus, Troodon, and Allosaurus. 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 Troodon, Maiasaura, and Diplodocus 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.

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 Jehelornis' cool new tail feathers and he signed my edition of TetZoo Book 1. 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.

Me (left), Dr. Darren Naish (middle) and my good friend Irlanda (right).

Another pic with Me, Dr. Jack Horner, and Irlanda

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 Abominable Science signed by him, chatted with Luis V. Rey for a bit and bought one of his art pieces, chatted with Paul Sereno about Eoraptor, 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 Chasmosaurus with skin impressions, and a talk about pachycephalosaur respiratory turbinates I was excited about just to name a few.

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 Scott Hartman 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.

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.

Saturday, Nov. 2: 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 Dogs: Their Fossil Relatives and Evolutionary History 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.

According to the talk given, modern pursuit hunting typical of Grey Wolves
might have been a recent invention. Previous species used other methods of hunting.

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 Anchiornis with new anatomical details, a possibly secondarily flightless Archaeopteryx, 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.

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. :)

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 Antediluvian Salad and Southland Beaver, who wrote a post that was a big inspiration for my Kem Kem video 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 Champsosaurus skull (I need to read more literature about those guys...). Finally I settled on purchasing an awesome pewter Styracosaurus pin, which now accompanies me every day I work at the museum.

First time I ever misidentified an extinct animal's skull.
Damn you, Champsosaurus...

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 Ceolophysis was seeing in its environs. (Peteinosaurus 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 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.

I then walked around for a bit, read some more posters on a possible new species of Edmontosaurus 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 the Romer-Simpson Prize for Lifetime Achievement — the highest honor one could receive from the Society.

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!

Stay sharp everybody!

Disneyland for Dinosaur Nerds

Stegoceras validum by John Conway
Why didn't you tell me you had respiratory turbinates!?

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...)

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.

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 here.

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.

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 and 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 nasal turbinates!!!

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.

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

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! :)

Thyreophora + Xenarthra = Fuzzy Ankylosaurus?

Beautiful amateur artwork by yours truly. But why the fuzz?

For those of you who have been checking my YouTube page, you may have noticed that I posted a new video, this time about the anatomy of the Ankylosauria. 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 Ankylosaurus magniventris, 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 Ankylosaurus 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.

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...

It suddenly seems a lot less cute after discovering about its drinking habits.
I wonder how Kristen Bell reacted to that discovery...

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.

The thyreophoran taxa Scutellosaurus (Padian 2004), Stegosaurus (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 Kentrosaurus, which might have had a faster growth rate (Redelstorff 2013). However, Kentrosaurus 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.

So, what does this all have to do with an Ankylosaurus 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.

The Shasta Ground Sloth, a desert-dwelling sloth that was completely covered in shaggy fur.
Other members of the group were the size of an Elephant and just as fluffy.

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 Eremotherium, which was the size of a small elephant, and its likely that the fur is present in still larger members like Megatherium.

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).

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?


Stegosaurus with tail spines made of porcupine-like filaments. Art by Mark Witton.
Looks like other scientists got the memo, or they're just slapping feathers on everything again...

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.

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.

Stay sharp! And make sure you check out my brand new Ankylosaur video on YouTube:

References:

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. Mammalian Biology doi:10.1016/j.mambio.2010.03.003

McNab, Brian K. (November 1980). "Energetics and the limits to the temperate distribution in armadillos". Journal of Mammalogy (American Society of Mammalogists) 61 (4): 606–627. doi:10.2307/1380307. JSTOR 1380307.

McNab BK (1985). Energetics, population biology, and distribution of Xenarthrans, living and extinct. In: Montgomery GG (Editor), The Evolution and Ecology of Armadillos, Sloths and Vermilinguas. Smithsonian Institution Press, Washington and London, 219-232.

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: 10.1671/0272-4634(2004)024[0555:gisdap]2.0.co;2.

Ragna Redelstorff & P. Martin Sander (2009) Long and girdle bone histology of Stegosaurus: implications for growth and life history, Journal of Vertebrate Paleontology, 29:4, 1087-1099, DOI: 10.1671/039.029.0420

Redelstorff, R., Hübner, T. R., Chinsamy, A. and Sander, P. M. (2013), Bone Histology of the Stegosaur Kentrosaurus aethiopicus (Ornithischia: Thyreophora) from the Upper Jurassic of Tanzania. Anat Rec, 296: 933–952. doi: 10.1002/ar.22701

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