Know Your Ankylosaurs: Mongolian Odds and Ends Edition

I'm back in civilization, so let's get back to ankylosaurs! Ready Set Go!

Gobisaurus, Zhongyuansaurus, and Shamosaurus

Shamosaurus is a really interesting ankylosaurid from the Zuunbayan Formation of Mongolia. Unlike later ankylosaurids, it still has a relatively long snout like you see in basal ankylosaurs and nodosaurids, and it lacks the distinctive tile-like skull ornamentation of ankylosaurs like Euoplocephalus or Saichania, instead just having a granular, pebbly texture on the skull surface. Gobisaurus, from the Ulansuhai Formation of China, is nearly identical in appearance, and only a few features distinguish these two taxa, namely the length of the tooth row relative to skull length and the orientation of the pterygoids. (Indeed, I think you could make an argument for subsuming Gobisaurus into Shamosaurus as Shamosaurus domoculus, but I'm generally reluctant to start making new combinations given that generic separation is pretty arbitrary anyway.)

Shamosaurus and its too-cool-for-school cervical half rings, on display in Moscow.

Gobisaurus and Shamosaurus are sister taxa; the name Shamosaurinae was proposed at one point and there's no reason to discard it at present even though it only contains two taxa. Shamosaurinae is the sister taxon to Ankylosaurinae. I also identified one new character that links Gobisaurus and Shamosaurus together which isn't present in other ankylosaurids: both taxa have a distinctive groove on each premaxilla, the purpose of which is unknown but there you go. There have been some suggestions that Cedarpelta (from North America) is also a shamosaurine ankylosaurid, and while I find the overall morphology of Cedarpelta to be pretty compelling for placing it in a clade with Gobisaurus and Shamosaurus, I didn't recover it with those taxa in my analysis (it came out more basally-positioned). However, I wouldn't be surprised if Cedarpelta winds up in Shamosaurinae at some point in the future as we find more specimens of both it and Gobisaurus and Shamosaurus.

Zhongyuansaurus was originally described as a nodosaurid ankylosaur partly because of its long snout, but it's indistinguishable from Gobisaurus (except for being smashed and flattened). The holotype is also a subadult (or at least not fully skeletally mature), since some of the cranial sutures are still visible towards the back of the skull. There are some interesting things going on with the postcrania of Zhongyuansaurus, but that's a story for a few weeks from now so STAY TUNED NO SPOILERS IF YOU'VE READ MY THESIS.

Tsagantegia

Of all of the more obscure ankylosaurs I looked at during my PhD, Tsagantegia might be my favourite for being the most surprising in person compared to what I had read about it. Tumanova included a line drawing of the specimen in her original description, which has been oft reproduced, but interestingly it doesn't really do justice to the original specimen (despite being a pretty nice drawing). The line drawing shows a long-snouted ankylosaur with amorphous cranial ornamentation, not dissimilar to Shamosaurus, but with a wider premaxillary beak more typical of later ankylosaurs. In person, however, the skull has distinct cranial caputegulae like we see in Euoplocephalus and Ankylosaurus! It's a pretty cool ankylosaur and I think it's probably really important to understanding the dispersal of ankylosaurs from Asia into North America and the diversification of ankylosaurids in the Campanian-Maastrichtian of Asia, but it's really hard to pin down the age of the Bayan Shiree Formation, and we don't have any postcrania for this taxon. I'm sure I'll be revisiting this guy in the future.

Heck yeah Tsagantegia!

Here it is again but in a more different view!

Talarurus

Way back when I originally started this blog in 2010, I had travelled to Korea to spend some time working in the Hwaseong paleo lab preparing Talarurus material and generally studying the ankylosaur material they had collected from the Gobi. Talarurus, like Tsagantegia, is also from the Bayan Shiree Formation but is clearly distinct. The holotype skull has very subtle cranial ornamentation that takes the form of small cones, rather than flat hexagonal tiles like Euoplocephalus, or bulbous pyramids like Saichania. Weirdly, this configuration is also present in the North American taxon Nodocephalosaurus – either this ornamentation style has convergently evolved, or, as I recovered in my analysis, these two taxa are closely related despite being fairly widely separated geographically and temporally. This is another ankylosaur that I'm sure we'll talk about again.

Talarurus butt in Moscow. The skeleton on display is a composite of several individuals from the same locality, and the skull is totally sculpted and a bit out of date.

Here's the holotype skull, with its weird, weird ornamentation.

Saichania

I've talked about Saichania fairly extensively here last year, but there were a few new things added in this most recent paper: Tianzhenosaurus and Shanxia (both from China) are, most likely, junior synonyms of Saichania, making this the most geographically widespread of the Asian ankylosaurids. Tianzhenosaurus has a nearly identical cranial ornamentation pattern when compared to Saichania, and I couldn't identify any differences that were outside of the usual ornamentation pattern variation we see in something like Euoplocephalus. Shanxia is known from the same formation but from a less well preserved skull, but the morphology of the squamosal horn is consistent with that of both Tianzhenosaurus and Saichania and therefore it probably represents the same taxon.

Next up: what's the big picture here, anyway?

A Body for Terrible Hands

It was a whirlwind year for dinosaur palaeontology, yet again. This week I'm writing about what I consider the most important news in my science field for 2014, for the Science Borealis blog carnival. There are so many great stories to choose from! Kulindadromeus and feather-like structures in ornithischians? The bizarro new reconstruction of a short-legged Spinosaurus? Both of those stories were pretty interesting, but my choice has to be the description of multiple skeletons of the Mongolian ornithomimosaur Deinocheirus.

If you like dinosaurs, there's a good chance you've heard about Deinocheirus before, even if it's not quite a household name like Stegosaurus or Triceratops. Deinocheirus (which means "Terrible Hands") was found during the Polish-Mongolian expeditions in the 1960s, and up until very recently has only been known by this single specimen, a pair of tremendous arms. And I do mean tremendous!

Me, in 2007, mimicking the 'zombie arms' of Deinocheirus, rather convincingly if I do say so myself.

A few years ago, the quarry for this holotype specimen was relocated and some gastralia (belly ribs) were found and described, but besides that this has been it. What on earth did the rest of this dinosaur look like? Was it a carnivore, herbivore, or something else? Where did it fit in the Cretaceous Gobi ecosystem?

While the exact evolutionary relationships of Deinocheirus have been enigmatic, there's been a general consensus that it was some kind of ornithomimosaur, or ostrich-mimic dinosaur. Even if you're not a dino-buff, you'll recognize ornithomimids as the stampeding dinosaurs in Jurassic Park – Gallimimus was the one 'flocking this way', and, conveniently, Gallimimus is a commonly encountered fossil in the Upper Cretaceous rocks of the Gobi Desert and would have lived alongside Deinocheirus. Where Gallimimus is an elegant, sprightly kind of dinosaur, Deinocheirus, it turns out, is not at all, not even a little bit.

It turns out that Deinocheirus is even more surprising than we would have ever guessed; the giant arms are nothing compared to the weirdness of the rest of its skeleton. Deinocheirus looks like a cross between a therizinosaur and a hadrosaur. It's a big, broad-bellied ornithomimosaur with a 'sail' of heightened neural spines on its vertebrae, and a widened, shovel-like snout with a deep jaw and tiny eyes. It looks like it was adapted for eating vegetation and had gastroliths preserved in its stomach region, but also had fish scales in there as well, prompting the authors to describe it as a megaomnivore, which is among my new favourite words of the year. Given that its close relatives the ornithomimids are known to have had feathers, as well as many other theropod dinosaurs, it is most likely that Deinocheirus had at least some feathers.

Deinocheirus, by the always-incredible Michael Skrepnick.

I will forever be jealous of my colleague Derek Larson, who was on the 2009 Korea-Mongolia International Dinosaur Project expedition that found the new skeletons of Deinocheirus (I was there just a year later, and it was a great year...but no Deinocheirus). I'm so thrilled that I've been able to see the original bones in person, and they really are quite something to see – I hope that the specimen will eventually be mounted and put on display so everyone can see it for themselves, too!

The "Canadian contingent" (which actually includes at least one American and one Australian, but let's not be too picky) at the 2013 Hwaseong International Dinosaurs Expedition Symposium last December, gawking away at Deinocheirus.

Deinocheirus is also an important reminder that Mongolian fossils are under threat. Sadly, many probably excellent skeletons are removed illegally from Mongolia every year – no fossils are allowed to leave the country without a permit, and none can be sold, so any fossils from "Central Asia" on the auction blocks are almost certainly stolen goods. The Deinocheirus skull had made its way out of Mongolia some years ago, and was, thankfully, repatriated to Mongolia when word of the new skeletons began to circulate throughout the palaeontological community. Incredibly, the skull actually belonged to one of the newly collected skeletons! This is a story that could have ended very differently – we might not have known about the strange skull of Deinocheirus because of fossil poaching.

Poached fossils make everybody sad! Here Phil Currie is showing the remains of a tyrannosaur skull that was improperly collected by poachers and destroyed in the process.

So why choose Deinocheirus over Kulindadromeus or Spinosaurus? Like I said, all three are top contenders for the most surprising finds of 2014. In some ways, the fuzz of Kulindadromeus is less surprising, and its significance lies in the fact that it lends support to the hypothesis that fuzz was present in most dinosaurian clades. Spinosaurus has also long been considered a specialist in aquatic foods, so while the new skeletal revision is certainly weird, it's not quite a fundamental re-envisioning of this beast. But Deinocheirus is way beyond what anyone would have ever predicted the rest of the skeleton would have looked like, and just goes to show that there are surprises waiting around every corner for us when it comes to dinosaur diversity. And, in my opinion, Deinocheirus leads to even more questions than it answered: what was it doing with that sail; why is its jaw so deep and its eyes so small; what kind of environment produces a megaomnivore like that; are any of the bits and pieces of what we thought was Gallimimus actually parts of juvenile Deinocheirus? I could go on and on.

Congratulations to my colleagues in Korea and Mongolia for organizing the Korea-Mongolia International Dinosaur Project expeditions – I'm sure this is just the first of many wonderful projects that will result from those years of fieldwork.

Thoughts on Tarbosaurus, part 4

Well, a lot has happened since the auction of a nearly complete Tarbosaurus was halted last May. At the end of December, Eric Prokopi surrendered his claim to the Tarbosaurus and other Mongolian and Chinese dinosaur fossils in his possession, and pleaded guilty to several charges surrounding the Tarbosaurus case. The Mongolian government is renewing its commitment to preserving its outstanding natural history heritage by creating a new dinosaur museum in capital city Ulaanbaatar, and several museums elsewhere in the countryside.

I hope the awesome leather Tarbosaurus makes the trip to the new digs.

Most recently, Paige Williams wrote an excellent article for the New Yorker interviewing many of the people involved in the Tarbosaurus case, including Prokopi. "Bones of Contention: A Florida man's curious trade in Mongolian dinosaurs" was an illuminating read for me, despite having followed the case closely. A few things struck a chord with me, because I was surprised by some of the attitudes displayed by people who are otherwise portrayed as 'passionate' about paleontology.

Prokopi started out as what seems like a pretty avid rockhounder and fossil buff growing up in Florida. Indeed, several previous news stories have portrayed Prokopi as simply doing what he loves. After university, he began selling fossils full time. He cleaned fossils, and sold small items to museums and nature centres. For the most part, this seems like pretty legit stuff. But then Paige quotes Prokopi: "One thing I was wondering is if any of these paleontologists you've talked to have given their argument of why paleontology is important...[fossils are] just basically rocks...It's not like antiquities, where it's somebody's heritage and culture and all that."

You can't have it both ways. You can't call yourself a 'commercial palaeontologist', co-opting the name of a scientific discipline, and then turn around and question the purpose or validity of palaeontology.

Later, Paige quotes Prokopi's wife Amanda: "And for what? For bones? No one's been murdered. We restored a dinosaur."

Tarbosaurus on display at the Mongolian Natural History Museum, in 2007.

So look, I get it. Stealing a dinosaur isn't as bad as murdering someone. And no, palaeontology isn't curing cancer or finding renewable energy or solving world conflict or any of those big-ticket items. But I'd like to think we live in a world where we don't have to funnel all of our resources into just the absolute bare minimum required to survive. I'd like to think that we have it in our hearts and our minds (and our pocketbooks) that we can study things that do not have immediate, direct, tangible, GIGANTIC benefits. I'd like to think that we live in a world where understanding nature and evolution and animals and biodiversity and our planet are TOTALLY OK things to spend one's time thinking about. Stealing a dinosaur doesn't have to be as bad as murder to still be a crime, and palaeontology doesn't have to cure cancer in order to have value.

I don't know what the take-away message from this post is, but I guess all of us in palaeontology and other sciences need to keep talking to the public, keep talking to policy makers, and keep trying to inject some enthusiasm for curiosity, exploration, and critical thinking into our everyday worlds. That's not too big a task, right?


For previous rants about this whole affair, see:
Thoughts on Tarbosaurus, part 1: in which I discuss the role of museums in conserving fossils.
Thoughts on Tarbosaurus, part 2: in which I discuss the identity of Tarbosaurus and how we know it's from Mongolia.
Thoughts on Tarbosaurus, part 3: in which I discuss why fossil poaching is a bad thing.

5 days to go...

The countdown is really on, now!

Here's a few shots of my previous visit to Mongolia, in August 2007. I feel very lucky to be able to have a second visit to such a wonderful place!

The ankylosaur bonebed Aleg Tag has produced many elements of Pinacosaurus, a small and unusual dinosaur. Unfortunately, the bonebed had been poached before we got there - you can see the small crater-like depressions where bones had been ripped up.

There were a few bones in the quarry. The Aleg Tag bones have a very rich red colour. This image shows a bunch of caudal centra that were lying around.

A slightly more impressive ankylosaur specimen is this nearly complete skeleton of the very spiky Saichania. This is definitely one of my all-time favourite ankylosaurs (oh, who am I kidding, I like them all....).



But Mongolia is much more than just ankylosaurs. The highly unusual and very small Mononykus was another treat to see while in Ulaanbaatar. Note that there is only a single huge claw on the hand!

I previously showed a photo of a cast of the Deinocheirus arms from my visit to Poland, but here are the real deal (with zombie paleontologist for scale).

But perhaps the most impressive dinosaur specimen EVER found is the amazing Fighting Dinosaurs, a Protoceratops and Velociraptor locked in combat. The Protoceratops bites down on the Velociraptor's wrist, while the Velociraptor's sickle claw is embedded in the throat of the Protoceratops. Nobody is exactly sure how this amazing scene came to be fossilized, but hypotheses include burial as a dune collapsed, or during a sandstorm.