Who-oplocephalus: Is Euoplocephalus ‘real’?

The holotype of Euoplocephalus isn’t very complete, as holotypes go. So, one of the first things I had to figure out for this project was whether or not the holotype of Euoplocephalus had any diagnostic features. Euoplocephalus was certainly unique when it was named – no other dinosaurs had the pattern of flat, polygonal plates on the skull like CMN 0210 has, and Lambe wasn’t even entirely sure what the cervical half ring was (he suggested it might have been the back of a frill or crest).

Here it is again: CMN 0210, holotype of Euoplocephalus tutus.

A lot of times, features that are unique or diagnostic to a species when it is named are later found to be present in other closely related dinosaur species. There’s a great term for this – character obsolescence (Wilson and Upchurch 2003). Anodontosaurus, named by Sternberg in 1929, had similar flat polygonal plates on the skull. And although Ankylosaurus was named in 1908, a skull was not known for some time – but it too has flat polygonal plates on the skull. So, this pattern isn’t necessarily a diagnostic or unique feature for Euoplocephalus.

Paul Penkalski looked at variation of skulls referred to Euoplocephalus in 2001, and noted that there were a couple of different morphologies represented by cervical half rings. Is the cervical half ring of CMN 0210 unique? Luckily for me, the University of Alberta has an excellent ankylosaur specimen called UALVP 31. Collected by GF Sternberg in 1921 and described by Gilmore in 1923, the skull has been on display in our paleontology museumfor several decades.

And here’s UALVP 31’s skull on display, plus the tail club UALVP 16247.

But more than the skull was collected – the cervical half rings, part of the hips and leg, a scapula, and other bits and pieces had been collected but never prepared! So, I dug out the half rings and other pieces and got to work.

Hop in the wayback machine, here’s a picture from 2007, my first year at the U of A, working on the cervical half rings of UALVP 31.

Preparing the material took a couple of years, because I did it in bits and snags around my research and other projects. I had help from several of my fellow grad students and technicians – Robin Sissons did the scapula, Mike Burns and Kristina Barclay helped with the pelvis, and Ian Macdonald and Clive Coy assisted with some of the trickier parts like the poorly-preserved second cervical half ring.

You guys, opening up old jackets is hard! Anyway, this is Mike and Robin in 2008 being awesome weirdos.

In 2009, I decided to supervise two high school students in the University of Alberta’s WISEST Summer Research Program. WISEST (Women in Scholarship, Engineering, Science and Technology) is an awesome organization that organizes conferences for junior high and high school students, and supports grad students, postdocs, and early career professionals on campus. Their Summer Research Program places high school students into university labs for about 6 weeks during the summer, and by the end the students produce and present a poster discussing what they’ve been up to. In 2009 I was joined by Carmen Chornell and Idel Riemer, who were enthusiastic and excellent fossil preparators! Together we completed preparing the UALVP 31 pelvis, as well as other small bits.

Carmen works away on the pelvis and leg…

…while Idel puts the finishing touches on some osteoderms.

The UALVP 31 cervical half ring turned out pretty neat, but I needed more information to figure out if the half ring of CMN 0210 was unique. I visited lots of museums to see what the half rings of other “Euoplocephalus” specimens looked like, and to see the half rings of other species of ankylosaurs. Thankfully, it seems that the half ring of CMN 0210 is diagnostic, so Euoplocephalus is a real taxon after all. The first cervical half ring has 6 tall, keeled osteoderms, and each pair has a distinct morphology. The middle (medial) pair are tall, with a centrally located apex to the keel. The lateral pair also have a keel, but it’s kind of sigmoidal (or, S-shaped). The distal pair, which cover the tips of the band, are flange-shaped. Some specimens, like UALVP 31, are missing the distal osteoderms – these don’t seem to fuse on as tightly, so it’s possible that they are more easily broken off before fossilization. The half ring of UALVP 31 shares the same morphology as CMN 0210, and so UALVP 31 was one of the few specimens that I could confidently refer to Euoplocephalus for a long time (another being AMNH 5406). UALVP 31 was the only one of these that had a complete skull.

On the left, CMN 0210, in the middle is UALVP 31, and on the right is AMNH 5406.

In the next post, I’ll talk about figuring out variation in the cranial ornamentation in Euoplocephalus skulls.


Arbour VM, Currie PJ. 2013. Euoplocephalus tutus and the diversity of ankylosaurid dinosaurs in the Late Cretaceous of Alberta, Canada, and Montana, USA. PLOS ONE 8: e62421.

Brown B. 1908. The Ankylosauridae, a new family of armored dinosaurs from the Upper Cretaceous. Bulletin of the American Museum of Natural History 24:187–201.

Gilmore CW. 1923. A new species of Corythosaurus with notes on other Belly River Dinosauria. Canadian Field Naturalist 37: 1–9.

Lambe LM. 1902. New genera and species from the Belly River Series (mid-Cretaceous). Geological Survey of Canada Contributions to Canadian Palaeontology 3: 25–81.

Lambe LM. 1910. Note on the parietal crest of Centrosaurus apertus and a proposed new generic name for Stereocephalus tutus. Ottawa Naturalist 14: 149–151.

Penkalski P. 2001. Variation in specimens referred to Euoplocephalus tutus. In: Carpenter K (ed.) The Armored Dinosaurs. Bloomington: Indiana University Press, 363-385.

Wilson JA, Upchurch P. 2003. A revision of Titanosaurus Lydekker (Dinosauria – Sauropoda), the first dinosaur genus with a “Gondwanan” distribution. Journal of Systematic Palaeontology 1:125-160.


Today I published a revision of the North American ankylosaurid genus Euoplocephalus. I’d like to take some time to go through some of the major points of the paper over the next few days here, but today I will give a brief introduction to the motivation behind this study.

Euoplocephalus is one of those ‘classic’ dinosaurs. Named in 1902 (as Stereocephalus, which was preoccupied by…a beetle! of course), it wasn’t known from very much material. All that Lambe had was a chunk of the snout/forehead region, and an unusual structure called a cervical half ring. Cervical half rings are totally bizarre structures that seem to be unique to ankylosaurids. They’re made of an underlying yoke of fused bone segments, and topped by fused osteoderms like you see on the rest of an ankylosaur’s body.

Canadian Museum of Nature 0210, holotype of Euoplocephalus tutus. On the left, the skull chunk. On the right, the first cervical half ring. Images modified from Arbour and Currie (2013).

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Dinosaurs 101

In addition to working through the home stretch of my PhD, an exciting project has kept me hopping for the last few months. I’m part of the team creating the University of Alberta’s flagship MOOC, in partnership with Udacity: Dino 101: Dinosaur Paleobiology. If MOOC is a new acronym for you, don’t worry – it was for me, too. There will be three flavours, so to speak, of Dino 101, but all will feature the same online content. Dino 101 will be available through Udacity, for free, to everyone around the world. Registered University of Alberta students who want to take the course for credit will register for PALEO 200 (online only), or PALEO 201 (same online content, but with additional in-person activities like field trips).

Working on Dino101 has been a great experience for me so far, even though it can be challenging. We’re working closely with educational specialists to make sure the pedagogy is sound, and that our assessments will be rigorous. We want to make sure that real learning will occur. We’ve spent a lot of time thinking about the foundational aspects of the course, like what our learning outcomes will be, and what skills will be tested. I’ve been learning a lot about educational theory – even though the scale of MOOCs is new, there’s a lot of people on board with this project who have researched the best ways to deliver and assess online content. We also have a great team working on unique interactives for the course, which should enhance the experience for students.

As we finish off scripts and move into production, I’m looking forward to seeing some of the cool ideas we have planned for teaching the basic concepts of dinosaur palaeontology come to life. I also hope that this course will serve as a springboard for people who are interested in animal biology and geology, and that everyone will come away with a better understanding of the scientific method.

I hope we’ll see you in Dino101 when we launch this September!

(Check out the UofA’s official Dino101 page for more information and to sign up for updates.)

Let’s Build the Currie Museum!

A message from my colleague Dr. Phil Bell:

Hi all,

Some of you are already aware of the Philip J. Currie Dinosaur Museum, which is scheduled to be built in Grande Prairie, but certainly all of you are aware of Philip Currie himself. As part of the final push to raise the remaining construction funds, we have launched a crowd-fundraising campaign on www.indiegogo.com/curriemuseum. The aim is to raise $1,000,000 in 120 days. In the first hour alone, we raised $1,600!

Every donation, no matter how small, is important and donors are rewarded with a range of increasingly cool gifts including a museum logo pin, t-shirts, and original artwork by palaeo-art master Julius Csotonyi. It’s all outlined on the website, so please check it out, spread the word, and help us build a world-class museum and research institute.

Many thanks!

Phil Bell

Head Palaeontologist

Pipestone Creek Dinosaur Initiative

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What I Did on My Summer Vacation: Happy Campers

This is Happy Jack’s (or as it used to be called, Old Mexico Ranch), an old homestead occupied by Happy Jack Jackson from 1903 to 1942. There are a couple of log cabins, some with cacti growing on the roof. Happy Jack’s is found on the north side of the Red Deer River in Dinosaur Provincial Park, and is the home base for the Currie Lab when we do fieldwork in DPP.  Continue reading

What I Did on My Summer Vacation: Danek Bonebed

The summer is over and school is back in session. Here in Edmonton the leaves already started to turn yellow last week. And somehow the summer got so busy that I hardly posted anything at all here. So, it’s nice to fix that up and talk about what I did on my summer ‘vacation’, by which I mean the time that undergrads are not at university but grad students are.

The ‘summer’ (which doesn’t really start until mid-June in Edmonton, but whatevs) started up with the PALEO 400 field school in early May. For three weeks, students help excavate the Danek Bonebed, a hadrosaur bonebed located right in the city (but in a secret location, to prevent vandalism). Over the course of those three weeks, they get to do everything: shoveling lots of dirt, uncovering bones with fine tools, plaster jacketing, carrying heavy things back to the truck, quarry mapping, field identification, you name it. Each student comes up with a research project related to the bonebed and writes a paper and/or presents a talk in October. This year we had five enthusiastic students and I am looking forward to hearing all about their projects later this fall.

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Cool Stuff

“Cool Stuff: The University of Alberta Museums Do Winter” is a winter-themed exhibit that opened last week at the U of A’s Enterprise Square location. I checked it out last weekend and was pleased to see so many different types of objects on display. We have 28 different collections on campus, and most (maybe all?) were represented in the exhibit – butterflies, moss, picked parasites, textiles, and more.  Continue reading

5 Questions for Phil Bell

Hot on the heels of yesterday’s interview with Caleb, here’s an interview with Phil Bell of the Pipestone Creek Dinosaur Initiative. Phil is a former Currie Lab member who completed his PhD last spring, focusing on the Mongolian and North American hadrosaur Saurolophus. He recently published a paper on skin impressions in Saurolophus. Thanks to David Lloyd of the Tyrrell Museum for the great photos of work at the Dragon’s Tomb in 2010! Continue reading