Sunday, October 5, 2014

Happy birthday, Dynamosaurus!

Today marks the auspicious anniversary of one of the most significant dinosaurs ever described: Dynamosaurus imperiosus! Surely one of the greatest and most fearful of all of the predatory dinosaurs, it stomped through the Maastrichtian of Wyoming and other parts of western North America. Dynamosaurus is noteworthy for its diagnostic dermal plates, which ran in transverse rows down its body and which formed a large knob of bone at the end of the tail. The function of these plates are still hotly debated, but they certainly gave Dynamosaurus a unique look among theropods.


I kid, of course, but I think Dynamosaurus deserves a mention on its more famous relative's naming day as well. Tyrannosaurus, Dynamosaurus, and Albertosaurus were all named by Osborn in 1905 and although Tyrannosaurus and Albertosaurus have proven to be distinct from each other, Dynamosaurus turned out to be a junior synonym of Tyrannosaurus. If Tyrannosaurus hadn't appeared first in the publication, good ol' T. rex might not be the household name it is today and we might all stand and gape at Sue or Scotty or Stan the Dynamosaurus. The distinctive osteoderms are probably Ankylosaurus osteoderms, although I haven't attempted to track down the specimens myself or any papers that discuss their identity, so I suppose they could also be Maastrichtian nodosaurid osteoderms.

Anyway, happy birthday, Dynamosaurus. I still like you, even if you never existed.



Osborn HF. 1905. Tyrannosaurus and other Cretaceous carnivorous dinosaurs. Bulletin of the AMNH 21: 259-265.

Osborn HF. 1906. Tyrannosaurus, Upper Cretaceous carnivorous dinosaur (second communication). Bulletin of the AMNH 22:281-296.

Friday, September 26, 2014

Know Your Ankylosaurs: New Mexico Edition!

There's a new ankylosaur in town - meet Ziapelta sanjuanensis from the Cretaceous of New Mexico!

Hello, Ziapelta! Many thanks to new Currie Lab MSc student Sydney Mohr for this wonderful life restoration of Ziapelta.

Ziapelta is represented by the holotype skull, first cervical half ring, and assorted other osteoderms, AND a referred first cervical half ring! (What are the odds of finding two really nice cervical half rings in the same field season? Bonkers!) It's a wonderful find from an area that seems to keep producing interesting dinosaur fossils.

Surprisingly, Ziapelta doesn't seem to be particularly closely related to the other ankylosaurid from the Kirtland Formation, Nodocephalosaurus. Instead, it's a close relative of Euoplocephalus and friends from Alberta – it shares the same general shape and pattern of cranial ornamentation, with flat, hexagonal caputegulae rather than the round, conical caputegulae of Nodocephalosaurus. Ziapelta is distinct from all of the Albertan ankylosaurids though: it's squamosal horns are thick and curve slightly downwards laterally, and its median nasal caputegulum is huge and triangular, rather than hexagonal. Somewhat bizarrely, Ziapelta has slightly bulbous or 'inflated' looking cranial caputegulae, not to the same extent as some of the Mongolian ankylosaurids like Saichania, but definitely moreso than Euoplocephalus or Anodontosaurus.


Cervical half rings once again prove to be taxonomically useful. Ziapelta has taller, more rectangular keeled osteoderms compared to Euoplocephalus, Anodontosaurus, and Scolosaurus, but does share the interstitial osteoderms present in Anodontosaurus.

Although we don't have the rest of the postcrania, we can assume that Ziapelta would have had a tail club since it is deeply nested within the clade of clubbed ankylosaurids. Did it have huge, triangular osteoderms like Anodontosaurus, a round tail club like Euoplocephalus, or a narrow tail club like Dyoplosaurus?

Ziapelta isn't the first ankylosaur described from New Mexico - in fact, it's just the latest in a string of interesting armoured dinosaur discoveries from there. At present, Glyptodontopelta is the only nodosaurid from the state, from the Maastrichtian Ojo Alamo Formation. It's known only from osteoderms, and mostly those from the pelvic region, but they're pretty distinctive and have a unique dendritic surface texture.

Glyptodontopelta bits at the Smithsonian.

Nodocephalosaurus is known from a partial skull from the De-na-zin Member of the Kirtland Formation. Its nodular cranial ornamentation is totally unique among North American ankylosaurids and more closely resembles the Late Cretaceous Mongolian ankylosaurids - an intriguing biogeographical conundrum that remains unresolved.

Nodocephalosaurus holotype skull at the State Museum of Pennsylvania. Check out those conical caputegulae!


Lesser known but deserving of more attention, my fellow labmate Mike Burns and colleague Bob Sullivan recently named another ankylosaurid from the stratigraphically lower Hunter Wash member of the Kirtland Formation. Ahshislepelta has a weird scapula with a strongly folded-over acromion process, as well as various other bits and bobs of the postcrania. Although there is little overlapping material between Ahshislepelta and Ziapelta, Ahshislepelta's osteoderms have a smoother surface texture, and the stratigraphic separate suggests we're probably looking at two different species.

Ahshislepelta holotype scapula at the State Museum of Pennsylvania.


Ziapelta is also neat because it (and Nodocephalosaurus) occur in a slice of time where we don't have very good ankylosaurid material in Alberta. In Alberta, we're in the lower part of the Horseshoe Canyon Formation – probably Anodontosaurus was found here around that time, but we don't have too many good specimens. Was it possible that Ziapelta roamed through the lower HCF? Or, are Ziapelta and Nodocephalosaurus characteristic of a southern Laramidian dinosaur fauna, like we seem to be seeing with some of the slightly older formations in Alberta (Dinosaur Park Formation) and Utah (Kaiparowits Formation)? Only more specimens will help us answer those questions.

I'm very grateful to Bob Sullivan, who found these specimens, for inviting me to help out with this paper, and to Spencer Lucas at the New Mexico Museum of Natural History and Science for his hospitality during my visit in 2012 to study the specimen. I hope one day I can have a chance to do some fieldwork in New Mexico, although I fear my thick Canadian blood would not serve me well and I would pretty much immediately die from the heat. Mike Burns and I had a great visit to Albuquerque in June 2012 to study the specimen, but boy howdy was it hot there. Ziapelta is housed at the New Mexico Museum and will be on display there, so if you're in the neighbourhood go say hi for me!

You can read all about Ziapelta in our open access paper in PLOS ONE!



Ninja-edit! I would be severely remiss in not linking to some of the thoughtful news coverage we were very lucky to receive for this paper!
* Brian Switek covers our research at Laelaps: "Ziapelta - New Mexico's newest dinosaur."
* Hear my weirdo voice on the CBC's Edmonton AM!
* And via the University of Alberta, "New dinosaur from New Mexico has relatives in Alberta."

More papers!

Burns ME, Sullivan RM. 2011. A new ankylosaurid from the Upper Cretaceous Kirtland Formation, San Juan Basin, with comments on the diversity of ankylosaurids in New Mexico. New Mexico Museum of Natural History and Science Bulletin 53:169-178.

Ford TL. 2000. A review of ankylosaur osteoderms from New Mexico and a preliminary review of ankylosaur armor. New Mexico Museum of Natural History and Science Bulletin 17:157-176.

Sullivan RM. 1999. Nodocephalosaurus kirtlandensis, gen. et sp. nov., a new ankylosaurid dinosaur (Ornithischia: Ankylosauria) from the Upper Cretaceous Kirtland Formation (Upper Campanian), San Juan Basin, New Mexico. Journal of Vertebrate Paleontology 19:126-139.

Thursday, September 18, 2014

Discovering Dinosaurs, Revealing Teamwork

It's a wonderful feeling when you get to be part of something that celebrates teamwork.
Yesterday was the opening reception for the University of Alberta's new exhibit, Discovering Dinosaurs: The Story of Alberta's Dinosaursas told through U of A Research. The exhibit features the work of almost all of the current people in Phil Currie's lab, as well as many of our alumni and colleagues.

The exhibit focuses in on research projects and new discoveries at the university. You'll see lots of fossils and casts, but you'll also see plenty of panels like this one featuring my work on ankylosaur tail clubs. (To see more of the folks in our lab featured in the exhibit, check out the DinoLab's Facebook album.) I really like this approach, because it shows that science is done by real people, and it shows the specific kinds of questions that we ask in order to tell the bigger stories about dinosaur lives. How DO we find out if ankylosaurs used their tail clubs as weapons? What kinds of techniques do we use? What surprises do we encounter as palaeontologists?


 
There's so many great stories in the exhibit, and I think the focus on dinosaur parts rather than full skeletons means we get to focus on the subtler bits of anatomy that might be missed in a room full of giant skeletons. (Not that I don't like a good room full of skeletons!). The exhibit is divided into several themed rooms – this one is obviously the theropod shrine, but you'll also get to see ankylosaurs, hadrosaurs, ceratopsians, and birds, and some non-dinosaurs, too!


Even vertebrate microsites get some love in the exhibit.


 
I think this is particularly fun – take a peek inside our camp kitchen tent in the Mongolian fieldwork room, and see some film footage from the early days of collecting at the university and from more recent work in the PALEO 400 field school at the Danek Bonebed.


 
Edmonton-based palaeoartist extraordinaire Julius Csotonyi provided much of the art you'll see throughout the exhibit, including life-sized restorations of the species featured in the exhibit. I think this is really effective – the specimens are the data, the research stories are the process, and the art shows how it all comes together in the end to reconstruct these extinct animals.


 
It's really cool to see some of the specimens I've only known as trays in cabinets come to life as full skeletons. On one level you 'know' how complete a skeleton is, but it's still a bit surprising, even to me, just how good some of our specimens are. We have good fossils, you guys!


 
This will probably sound corny, but it was somewhat emotionally moving for me to see UALVP 31 all laid out and on display. This was one of the most important ankylosaur specimens for my work on revising the taxonomy of Euoplocephalus, and I did a lot of the prep work on the postcrania in conjunction with my colleagues Mike Burns, Robin Sissons, and Kristina Barclay, and with WISEST summer research students Carmen Chornell and Idel Reimer. (See what I mean about teamwork?). We also added in UALVP 47273 waaayy down at the other end, the tail club that Phil Bell found the year before I joined the lab and which was super important for my work on tail club biomechanics.


I'll finish off here, but know that this is only a tiny sampling of what's in store for you at the exhibit. I hope you'll check it out and learn something new. Discovering Dinosaurs is on display at the Enterprise Square Galleries in downtown Edmonton from now until January 31st, 2015. There's a great series of K-12 education programs associated with the exhibit, as well as a fun program of speakers and events for the general public over the next few weeks (if you want to hear more about ankylosaurs, I'll be speaking on September 27th!). You can also check out our permanent exhibit in the Paleontology Museum in the Earth and Atmospheric Sciences Building on campus. Not in Edmonton? You can still join the fun with Dino101, our massive open online course that's currently underway at Coursera.

Wednesday, September 10, 2014

What's new with Dino 101?

The third offering of Dino 101 kicked off again last week, and we're already into our 2nd lesson, on taphonomy and fossilization. Here's a quick update for what's new this time around!
  • A new section about the palaeobiogeography of dinosaurs was filmed, including lots of new scenes at the Royal Tyrrell Museum
  • We get to show off the Edmontosaurus with the "cock's comb"!
  • We added in some more information on non-dinosaurian critters from the Mesozoic throughout the course, including pterosaurs, marine reptiles, and early mammals
  • I made a bunch of new 3D models for our fossil viewer interactive – now you can enjoy the baby chasmosaur's skull in three dimensions of terror and amazement!


These are all in addition to some of the snappy upgrades to version 2, like the section on the baby chasmosaur and the fancier study guides.

So far there's more than 11 000 students registered in Dino 101 v3, which means we've now reached nearly 50 000 students from around the world! The on-campus versions of Dino 101, including the flipped/blended PALEO 201, are also underway, and the PALEO 201 team is making some new activities about dinosaur footprints and trackways. I'm sure they're going to have a great time!

You can join the fun at Dino 101 for free - register now at Coursera! And you can follow the course in its various social media forms, including Facebook and Twitter.

Friday, July 25, 2014

Big screaming hairy dinosaurs.

Kulindadromeus, a little ornithischian from the Jurassic of Siberia, has the palaeosphere abuzz with talk of fluff, feathers, scales, and all kinds of interesting integumentary goodness. Kulindadromeus has scales on its feet, hands, and tail, but the head, body, and upper limbs are covered in three different kinds of filamentous integument. 

Beautiful restoration of Kulindadromeus by Andrey Atuchin, via National Geographic.

Feathers and fluff are extensively known in coelurosaurian theropods (and possibly other theropods as well), but are more controversial in ornithischians. Bristle- or quill-like structures are known in the little ceratopsian Psittacosaurus, and in the 'heterodontosaur' Tianyulong, but since these structures are so different than the filaments and feathers of theropods, there's been some debate about whether or not they evolved independently of true feathers.



A not-so-great photo of a cast of the quilled Psittacosaurus specimen at the Carnegie Museum (look towards the top of the photo for the long, thin filaments), and a life restoration in the museum as well.



In Kulindadromeus, the torso and head are adorned with simple filaments that are thinner than the quill-like bristles in Psittacosaurus and Tianyulong. There are tufted plumes, where multiple filaments converge to a scale-like base, on the upper arm and upper leg. Finally, there are some ribbon-like clusters of filaments on the shins. The tufted plumes still aren't really like anything in the theropods, but the fact that they are branching filaments certainly suggests these are more feather-like than the quills of other ornithischians.

Besides its amazing fluff, Kulindadromeus is pretty neat for a couple of other reasons: 1) we don't really have a lot of dinosaurs from Siberia, so anything new from this region is cool!, and 2) basal things are always interesting, and 3) its non-feathery integument is super interesting! Kulindadromeus is a little more derived than Agilisaurus or Stormbergia, but is still in a relatively basal position in Neornithischia, the clade of ornithischian dinosaurs that includes everything except thyreophorans (ankylosaurs and stegosaurs), 'heterodontosaurs' like Heterodontosaurus, Fruitadens, and Tianyulong, and the most basal ornithischians like Pisanosaurus. The scales on its tail remind me of aetosaur osteoderms, but lack any bone and so aren't osteoderms, but true epidermal structures.

Anyway, I've been thinking about dinosaur skin a lot lately, having written papers on ankylosaur scale pattern diversity and soft-tissue crests in Edmontosaurus. In particular, I'm intrigued by the idea of scaly and fluffy ornithischians. We know that hadrosaurs and ankylosaurs had scaly skin, but does that preclude having fluff too? Well, Kulindadromeus shows you can totally have skin and fluff in different regions of the body. On the other hand, lots of large mammals today lack hair over most of their body, so large dinosaurs may have done the same.

Most of the ankylosaur skin impressions I know of come from Alberta, where the conditions are not ideal for preserving feathers and fluff. However, it's not impossible – feathers have been reported from ornithomimids from Alberta, so maybe we just need to look more carefully in the future. I think the idea of a fluffy ankylosaur probably seems preposterous – how could such an armoured, osteodermy animal have filaments in addition to its tough scales? And it's true – most animals today with osteoderms, like crocodiles, turtles, and lizards, don't have fluff. But there's one group of animals around today that very definitely have osteoderms and fluff:

Via Arkive.

Here's the big hairy armadillo, Chaetophractus villosus. It's one of the fuzziest of the armadillos, with lots of coarse hair on its belly, but also hairs growing off of the individual scutes (if I understand correctly). I'm not going to argue that ankylosaurs definitely had this kind of morphology – armadillos, being mammals, have totally different osteoderms than ankylosaurs that evolved on their own independent evolutionary pathway, and mammal hair/skin and ankylosaur skin are very different. Additionally, we now have evidence for branching filamentous structures as far back as Neornithischia, but ankylosaurs lie outside of that clade (Tianyulong, with its quills, is more basal than ankylosaurs). But being an armoured, osteodermy animal does not always rule out also being a gross hairy thing. Because seriously, look at that guy.

So here, have a big hairy Pseudoplocephalus. He's not so bad, is he?



Or better yet, make it a screaming hairy Pseudoplocephalus, like Chaetophractus vellerosus.




Papers! (And if anyone has any literature on big hairy armadillos, please send it my way!)

Arbour VM, Burns ME, Bell PR, Currie PJ. 2014. Epidermal and dermal integumentary structures of ankylosaurian dinosaurs. Journal of Morphology 275:39-50. [Paywalled! Accessible post here.]

Bell PR, Fanti F, Currie PJ, Arbour VM. 2014. A mummified duck-billed dinosaur with a soft-tissue cock's comb. Current Biology 24:70-75. [Paywalled! Accessible post here.]

Godefroit P, Sinitsa SM, Shouailly D, Bolotsky YL, Sizov AV, McNamara ME, Benton MJ, Spagna P. 2014. A Jurassic ornithischian dinosaur from Siberia with both feathers and scales. Science 345:451-455. [Paywalled! Accessible post here.]

Mayr G, Peters SD, Plodowski G, Vogel O. 2002. Bristle-like integumentary structures at the tail of the horned dinosaur Psittacosaurus. Naturwissenschaften 89:361-365. [Paywalled! Accessible post here.]

Zelenitsky DK, Therrien F, Erickson GM, DeBuhr CL, Kobayashi Y, Eberth DA, Hadfield F. 2012. Feathered non-avian dinosaurs from North America provide insight into wing origins. Science 338:510-514. [Paywalled! Accessible post here.]

Zheng X-T, You H-L, Xu X, Dong Z-M. 2009. An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures. Nature 458:333-336. [Paywalled! Accessible post here.]

Thursday, May 22, 2014

Did the sauropod Leinkupal survive the End Cretaceous mass extinction?

No.

Discovery News has a short video up discussing a new paper in PLOS ONE, Gallina et al.'s "A diplodocid sauropod survivor from the Early Cretaceous of South America". I think it is really great that they want to showcase this interesting new find! But the DNews report leaves an awful lot to be desired.



The news report is titled "There's a dinosaur that survived mass extinction!", which would lead most people to think that some kind of post-Cretaceous dinosaur has been discovered. At about 25 seconds in, the reporter says this is the first time scientists have found a dinosaur that survived the great extinction, presumably referring to the End Cretaceous mass extinction that happened 66 million years ago. Right away, it seems that there's a huge misunderstanding here – there have been multiple mass extinctions in the history of life, not just the one that killed the non-avian dinosaurs. Additionally, the 'great extinction' should really refer to the End Permian extinction, by all accounts the most devastating mass extinction ever.

Anyway, Gallina et al. have described a new diplodocid sauropod, called Leinkupal, from the Early Cretaceous (probably about 140-130 million years ago) in Patagonia. This is significant because diplodocid sauropods were pretty abundant in Jurassic rocks from North America, Europe and Africa, but seem to have disappeared from the fossil record after the Jurassic. Since diplodocids were present in the Jurassic of Africa, it was also thought that they were probably present in the Jurassic of South America, but no fossils had ever been found. So, Leinkupal confirms one hypothesis (that diplodocids were present in South America), and also rejects another (diplodocid sauropods went extinct at the end of the Jurassic). Good stuff all around! But Leinkupal does not tell us that dinosaurs survived the 'great extinction' (whatever that is), and it certainly did not survive the End Cretaceous extinction, on account of it having been dead for about 70 million years before that happened.



This little video is an amazing microcosm of misconceptions about evolution and palaeontology, and it's really frustrating to see this coming from Discovery News. Here's some other little snippets:

* "The diplodocid sauropod is a family" – I hate to nitpick over grammar (wait, who am I kidding – I love nitpicking over grammar!), but the grammatical failure here I think represents a pretty basic misunderstanding of how taxonomy works. Later on, the reporter says of diplodocids that "the species was thought to be an exclusively North American dinosaur". Diplodocids are a subset of sauropods, in the same way that sauropods are a subset of dinosaurs. Diplodocidae is the formal 'family' name for this group, and Diplodocidae contains many genera and species. Some of these are familiar, like Diplodocus and Apatosaurus, some are less familiar, like Tornieria and some are new, like Leinkupal. We use classification systems to understand how animals are related to each other, and to understand the scale of certain biogeographic patterns. Getting this stuff right is both relatively easy and also important!

The imposing figure of "Seismosaurus" hallorum, a diplodocid from New Mexico on display at the New Mexico Museum of Natural History & Science. "Seismosaurus" is thought by some authors to be the same genus as Diplodocus.

*At one point, the reporter says that diplodocids were "assumed to have gone extinct", which is kind of true but also takes a lot of the science out of the story! Palaeontologists didn't just assume diplodocids were extinct, they observed the pattern in the fossil record in which diplodocids were present in some layers and then not in others, and concluded that either 1) diplodocid sauropods went extinct at the end of the Jurassic or 2) we have incomplete data, and sauropods may just not be preserved in the post-Jurassic rocks we've looked at. It turns out that the latter idea was correct!

* The reporter comments that the Patagonian discovery is the earliest record of diplodocids. It's easy to get mixed up with this sometimes, but Leinkupal represents the youngest, and therefore latest record of the group. The earliest record of a group would be the first record, and therefore the oldest record. Since this is the main point of this story, they should really get this right!

* The reporter also states that Leinkupal was found in a place that palaeontologists never expected (South America), when in fact the biogeographic pattern of known diplodocids hinted strongly at the possibility of South American diplodocids. This is so great! We were able to use our knowledge of the fossil record to predict where we might find a kind of dinosaur that we had not found there before.

* Finally, the segment opens with the reporter making a show of how hard it is to pronounce the new dinosaur's name. It's true that Leinkupal doesn't have the familiar Something-saurus structure that lots of dinosaurs have, but it's not overly difficult to pronounce. There are two things that bother me here: 1) Why, Discovery News, are you making your female presenter pretend to be dumber than she surely is? and 2) An unfamiliar foreign word is made out to be this super weird and difficult thing, when they could have taken a moment to point out that this unusual name means "Vanishing family" in Mapudungun. It's a beautiful and evocative word that reflects the significance of the specimen, and highlights a local language that most of us are not familiar with. A moment that could have been used to learn something new was instead used to indicate that new things are weird and learning is hard.

This is really shallow and lazy writing. All of the important points to cover in a video segment of this length can be found in the three-paragraph introduction of the open-access paper. There's no excuse to not get it right. Instead of highlighting how this discovery shows the power of scientific predictions, we got a video that can't get basic facts correct, and pretends that this stuff is really hard rather than working to make it accessible to everyone.

Friday, May 16, 2014

Many animals have skeletons besides dinosaurs.

I was reminded of an old post on this blog today when someone brought up the all too common question of "Is that real?" in museums. In 2011 I had visited the Smithsonian natural history museum for some of my Euoplocephalus research, and spent a day browsing the galleries and shamelessly eavesdropping on people's conversations. I was dismayed by the number of people saying things like "What's that!" and then walking away without finding out, or saying "Look, a T. rex!" to things that were patently not T. rex. In the comments on that post, there was some discussion of the fact that visitors to museums often mistake any skeleton as a dinosaur skeleton.

Anyway, that in turn reminded me of a photo I took in the Nova Scotia Museum of Natural History's marine gallery a while ago:


Despite being surrounded by all manner of marine specimens, including a fleshed out model of a sei whale up above, the museum has to explicitly say that a pilot whale is not a dinosaur. In fairness, the museum (sadly!) does not have any dinosaur skeletons, what with Halifax being located on top of the Cambrian-Ordovician Meguma Terrane, and with the Fundy Geological Museum fulfilling the role of the dinosaur-having museum in Nova Scotia.

What lessons can we learn from this?
1. Museum people: put a dinosaur in your museum. There's no excuse not to have one.
2. Everybody else: many animals have skeletons besides dinosaurs.
3. ????




*Bonus! Sable Island is a super neat place that not many people have heard about outside of the maritime provinces - you can read more about it at their National Park page!