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.