What's up at Wapiti River?

The world can always use some more Pachyrhinosaurus bonebeds. So hooray to my friends and colleagues Federico Fanti and Mike Burns, and my PhD supervisor Phil Currie, for publishing a description of the Wapiti River Pachyrhinosaurus bonebed (currently in 'early view' accepted manuscript form at the Canadian Journal of Earth Sciences).

A friendly Pachyrhinosaurus lakustai greets students at Grande Prairie Regional College!

Most of the time, dinosaur palaeontologists look for bones in dry, barren landscapes – the badlands of Alberta, the Gobi Desert, etc – places that have lots of rocks and not much covering them up, like inconvenient forests or cities. But sometimes, you don't have vast expanses of outcrop. In Nova Scotia, we dig up dinosaurs on the beach. In the area around Grande Prairie, Alberta, you look for bones in the outcrops along rivers and streams.

The very first summer I went out with the University of Alberta crew (way back in the halcyon days of 2007; the first Transformers movie was 'good', everybody read the last Harry Potter book overnight to avoid spoilers, and...apparently not much was happening in my musical spheres, but my, how time has flown), there wasn't a Wapiti River bonebed. We knew that there were bones coming out of the riverbank somewhere, but it took the better part of a day to trace them up the hill to the bone layer. 

See if you can spot Phil for scale way up on the hill there, and remember that Phil is about 3x as tall as most humans. That's where the bone layer is!

It's a pretty steep hill, and so those first few days excavating the bone layer meant hacking out little footholds and gradually making enough of a ledge for us to sit on and walk around each other without plummeting to our death.

The last time I was there, in 2011, the ledge had expanded significantly, although you can see it's still a pretty narrow slice! It's a scenic place to work, with the river and boreal forest stretching away below; bear sightings were not uncommon (and occassionally closer than we'd all prefer), and I remember a hummingbird came down to check on us one day, buzzing around my head for a few moments!

In this bonebed, there's a layer of bones in a crazy, mixed-up layer of folded mudstones, and those are pretty easy to excavate. 

Here's a dorsal vertebra. Nice and easy.

But down beneath that, the skulls and larger bones are encased within super hard ironstones. We can't really do much with these in the field, so we need to take them out in huge pieces. 

And here's what the skulls look like. The circular depression down towards my left foot is the narial opening. The UALVP has like 15 of these suckers and they each take about 2 years to prepare with a crack hammer and chisel.

But the bonebed is also about halfway down into the river valley on a steep slope that's hard enough to just haul yourself up, let alone a huge boulder. So we've been very lucky to have helicopter support to carry out some of the heaviest pieces at the end of each field season.

Up, up and away!

Sometimes we were even visited by Aluk the Pachyrhinosaurus, mascot of the Arctic Winter Games in 2009!

This was probably the strangest day in the field.

There's still much more work to be done on this bonebed – we still aren't exactly sure what species of Pachyrhinosaurus is present. The age is right for P. canadensis, but only time will tell. And with two Pachyrhinosaurus bonebeds in Grande Prairie – the Pipestone Creek bonebed with P. lakustai, and the slightly younger Wapiti River bonebed – there's bound to be much more to learn about the evolution and biology of this unusual ceratopsian. 

Previously in Pachyrhinosaurus:
Wapiti River Fieldwork, Part 1
Wapiti River Fieldwork, Part 2

And don't forget to check out:
Fanti F, Currie PJ, Burns ME. 2015. Taphonomy, age, and paleoecological implication of a new Pachyrhinosaurus (Dinosauria: Ceratopsidae) bonebed from the Upper Cretaceous (Campanian) Wapiti Formation of Alberta, Canada. Canadian Journal of Earth Sciences, early view.

The Great Canadian Dinosaur Hunt

Dino Hunt Canada is almost here! Starting this Friday, History Channel Canada will be airing a series of hour-long documentaries devoted to dinosaur expeditions all across Canada - and not just in the famous badlands of Alberta! The production crew visited field localities in Nova Scotia, Saskatchewan, multiple places around Alberta, and British Columbia. It's going to be a real who's who and where's where of Canadian palaeontology.

I'll be in the second episode featuring work in Dinosaur Provincial Park, which we filmed in 2013. It was a fun if somewhat unusual experience to have such a large film crew with us, and I'm looking forward to seeing the whole shebang!

What was the crew filming in DPP? Tune in to find out!

There's also a really excellent website to accompany the show. You can learn more about some of the dinosaurs featured in the series (including wonderful new artwork by Danielle Dufault!), see interviews with some of the palaeontologists, and submit ideas for a nickname for a new dinosaur excavated during the show by the Southern Alberta Dinosaur Project. You can even submit questions and maybe have my weirdo face answer them via Skype! All in all, it's looking really good so far and I'm so happy to see the huge variety of dinosaur research being conducted across Canada by so many talented and hardworking people.

Edmontosaurus in Edmonton

Happy 2015, readers! So many exciting things are happening right now – the Dino Hunt Canada website launched a few weeks ago and the documentary will air on History Channel Canada later this month, things are chugging away here in North Carolina, and the Danek Edmontosaurus Bonebed special issue of the Canadian Journal of Earth Sciences was published just before Christmas. There's already been lots of great coverage of the special issue, but I wanted to share a few thoughts here as well.

Please enjoy these very fine Edmontosaurus bones!

The special issue on this bonebed came about when Mike Burns and I got to talking about how the Albertosaurus Bonebed special issue had been such a good motivation for the lab to do some collaborative projects, and given that the PALEO 400 fieldschool students needed to develop research projects on the bonebed, wouldn't it make sense to try to polish those into publishable form as well? This was back in 2012, and at that point there'd been 6 years of really good fieldschool students who had come up with a variety of interesting small-scale independent research projects. We put out a call to current and former students to see if anyone would be interested in expanding their project and contributing it to the volume, and also invited some of our colleagues who were working on hadrosaurs and/or bonebeds in some way to see if they would be interested in working on the material as well. Not all of the former students contributed papers, but I was really pleased by the number who did – it's a big job to get a paper through peer-review, and I'm really proud of all the first-time papers in this issue!

Albertosaurus tooth!

It's also been really rewarding to watch our volunteer fossil prep program grow over the years I was at the UofA – we started with a few volunteers here and there, but in recent years we've had as many as 8-12 people working in the lab on a weekday evening. We run two shifts of volunteers – an evening program from 5-7pm on some combination of Mondays to Thursdays, depending on the schedules of the grad students who supervise the volunteers, and a daytime program by appointment in our larger basement laboratory with the larger and more challenging projects. Most people start in our evening lab programs, and many of the bones prepared during those hours were from the Danek bonebed. The Danek material is amazingly good for volunteers – with a bit of soaking, the surrounding shaley matrix flakes off the relatively durable bones. We would never have gotten through all of that material so quickly without the dedicated help of a very large crew of volunteers! If you're reading this from Edmonton and are interested in volunteering in the DinoLab, follow our Facebookpage for up-to-date contact information and hours.

Ian is a shoveling machine!

Although I haven't gone out to the bonebed for the full 3 weeks each year, I've tried to get out at least a little bit each year, even if it's only for 'overburden removal' days. It's amazing how much dirt we've moved since my first year there in 2007! Because the bonebed is located in a nature preserve, we need to be a bit careful with how we handle the overburden – we can't let too much sediment get into the creek, and we also can't just cover up existing plants. What we've taken to doing is removing the topsoil from a 'meadow' nearby, evenly spreading the relatively sterile Quaternary sands/gravels in the clearing, and then 'replanting' the topsoil overtop and sprinkling with local plant seeds. We dig in the early spring, and by July the area is so green you'd never even know we had disturbed it. The bonebed is a beautiful place to work - we see lots of interesting wildlife because of the stream nearby, the matrix surrounding the bones is soft and incredibly easy to work with, and the bones are plentiful.

Clearing the 'meadow'.

Sometimes it's cold in April in Edmonton!

One of the things we mentioned in the press materials for the special volume is the presence of other dinosaur fossils throughout Edmonton and the surrounding areas. I have a hunch that if you dig pretty much anywhere in Edmonton, you're probably going to hit a dinosaur bone at some point. There've been dinosaurs in the sewers and dinosaurs in the pipelines, and dinosaur bones pop up along the North Saskatchewan River with relative frequency. If you think you've found a dinosaur bone in Edmonton, make sure you understand the laws protecting fossils in Alberta – you need a permit to dig up fossils in Alberta, and fossils should be stored in accredited facilities like the Royal Tyrrell Museum of the University of Alberta Laboratory for Vertebrate Paleontology. But if you find something, tell the University of Alberta about it! Take a picture of what you found, and if you have the ability to mark the latitude and longitude with a GPS or your phone, do that too. You can get in touch with us via the DinoLab Facebook page. Maybe you will be the next person to stumble across a dinosaur in your city!

Not in Edmonton? The Danek Bonebed is where much of the taphonomy and fieldwork lesson for Dino101 was filmed! The 4th session of Dino101 started today, so go have a look if you're interested in learning more about the bonebed.

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 31^st, 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.

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.

Scaling Up

Let's turn our attention from hadrosaur skin to ankylosaur skin, a topic which has received surprisingly less attention in the published literature than I would have thought. I should qualify that statement, however, by saying that by 'ankylosaur skin' I mean ankylosaur skin impressions, because ankylosaur dermal elements are well known and the focus of many a paper – I refer of course to osteoderms, which form within the dermis of the skin and which give ankylosaurs their spiky and armoured appearance.

For a couple of years now I've been keeping notes about occurrences of skin impressions in ankylosaurs, which eventually lead to a paper by myself, Mike Burns, Phil Bell, and Phil Currie. We reviewed the morphology of scale patterns in the few specimens that preserve skin, and found that there were some intriguing differences in scalation between different ankylosaurs.

The holotype of Scolosaurus cutleri, NHMUK R5161, has the best preserved integument for any North American ankylosaur, and has loads  of scale impressions lying overtop of the in situ osteoderms. In Scolosaurus, the scales form rosettes around the osteoderms. The largest scales are generally found closest to the osteoderms, but some large scales are scattered in between the osteoderms as well. Underneath the scales, small ossicles (little osteoderms less than 1 cm in diameter, but usually only 2-4 mm wide) fill the spaces between the larger osteoderms.

Scolosaurus is hard to photograph well, sorry!

In contrast, a very unusual specimen (ROM 813) has a completely different morphology. This specimen includes unusual long, rectangular osteoderms that aren't present in NHMUK R5161. The scales are on average much smaller, don't form much of a rosette pattern around any of the osteoderms, and are more uniform in size overall. ROM 813 is a little bit difficult to interpret because it is partially disarticulated (which is also intriguing given that such large portions of the integument are intact), but our best guess for the preserved portions is shown here.

Another super cool thing about ROM 813 is that it preserves the epidermal covering of an osteoderm, and it is the only example of this in an ankylosaur that I know about. In the photo below, the smooth side of the osteoderm is the epidermal scale, and the rough side of the osteoderm is the true bony part of the osteoderm.

Moving over to Mongolia, a specimen referred to Tarchiagigantea lacks the small pavement of ossicles seen in the Albertan ankylosaurs, and the epidermal scales are huge and more rectangular. In the portion of the integument preserved, osteoderms are separated by only one row of scales.

There's enough overlapping material between these specimens to allow us to compare scale patterns among different ankylosaurs, and the differences support the hypothesis that these are different taxa. Unfortunately, right now we can't assign ROM 813 to any known ankylosaurid taxon from Alberta – this could represent the postcrania of Euoplocephalus tutus, or Dyoplosaurus acutosquameus, or (less likely) a new taxon of ankylosaurid from the Dinosaur Park Formation. I think it's safe to say that the differences between Scolosaurus and ROM 813 represent true taxonomic differences, a finding that is in line with previous work by Phil Bell on scalation differences between Saurolophus angustirostris and Saurolophus osborni.

Illustrations by Lida Xing and via PLOS ONE.

One more comment about ankylosaur skin: In 2010 I had the opportunity to study the holotype of Liaoningosaurus paradoxus, and very interesting little ankylosaur from the Liaoning Formation of China. The original authors described Liaoningosaurus as possessing a ventral plastron (bony shield, like that found in turtles), which would have been a highly unusual anatomical feature given that no other ankylosaurs possess a plastron. Having looked at this specimen, I think a better interpretation for the plastron is that this is a segment of skin impressions from the belly region – there didn't seem to be any bony texture around the edges of this area, and the pattern is more consistent with scales than any osteoderms in other ankylosaurs.

Belly scales for Liaoningosaurus. The scale bar is in millimetres.

Papers!

Arbour VM, Burns ME, Bell PR, Currie PJ. 2014. Epidermal and dermal integumentary structures of ankylosaurian dinosaurs. Journal of Morphology 275:39-50.

Arbour VM, Lech-Hernes NL, Guldberg TE, Hurum JH, Currie PJ. 2013. An ankylosaurid dinosaur from Mongolia with in situ armour and keratinous scale impressions. Acta Palaeontologica Polonica 58:55-64. Many thanks to Dr. Hurum for inviting me to help describe this specimen!

Bell PR. 2012. Standardized terminology and potential taxonomic utility for hadrosaurid skin impressions: a case study for Saurolophus from Canada and Mongolia. PLOS ONE 7:e31295.

Xu X, Wang X-L, You H-L. 2001. A juvenile ankylosaur from China. Naturwissenschaften 88:297-300.

Cock-a-doodle-doo

I've finally got the time and gumption to sit down and write again, so let's do some research blogging! And let's show some skin while we're at it!

The first paper I'll talk about is not one that I'm lead author on, but which was a really fun project to be involved in. This was the description of a super cool specimen of a hadrosaur from the area around Grande Prairie with some impressive skin impressions. UALVP 53722 was collected as a large block that had fallen along the creekside. Unfortunately, the rest of the skeleton could not be located, which might mean it's still in situ somewhere with nothing visible, or it had already broken apart into unrecognizable pieces. The block preserves the back of the skull with the neck arched over the shoulders, the classic 'death pose' seen in many dinosaur skeletons. Most of the skull is missing, but what is present shows that it is an Edmontosaurus regalis, the slightly older species of Edmontosaurus. 

Flat-headed Edmontosaurus at the Denver Museum of Nature and Science.

And sitting on top of the skull is a round, relatively smooth lump of soft tissue, like the comb on a rooster's head. 

My primary contribution to the paper was to examine the CT scans of the specimen to confirm that there wasn't a bony structure within the crest, so that we could be confidant that it truly was a soft tissue structure only. The UofA put together a short video about CT scanning the fossil that is worth a watch:

The fleshy comb in UALVP 53722 the first time we've seen anything like this in a dinosaur, and was totally unexpected – Edmontosaurus is one of the 'flat-headed' hadrosaurs that lacks the bony crest characteristic of lambeosaurines like Corythosaurus or Lambeosaurus. I love this discovery because it is such a great example of how much soft tissues contribute to the appearance of an animal. It also goes to show how a new fossil, even for a relatively well known dinosaur like Edmontosaurus (which is known from many skeletons and bonebeds) can still give us new information. 

Crested Edmontosaurus based on UALVP 53722.

I was also a big fan of the book "All Yesterdays", and I feel like this specimen kind of fits in with some of the more adventurous reconstructions of dinosaurs with elaborate soft tissues that have become more fashionable of late. And like all good discoveries, we end up with more questions that need to be answered: did all Edmontosaurus regalis have this fleshy comb, or was it restricted to adults, or even just adult males? If males and females both had the comb, was it larger in one sex than the other? Was it brightly coloured? Did Edmontosaurus annectens have a fleshy crest? We'll only be able to answer these questions with more specimens.

Anyway, go check the paper out! UALVP 53722 was on display in Edmonton for a short time earlier this year – stay tuned for more information on where it will be on display next! Many thanks to Phil Bell (a former Currie Lab student and now at the University of New England in Australia) for inviting me to help out with this paper.

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.

Horner JR. 2014. Paleontology: a cock's comb on a duck-billed dinosaur. Current Biology 24.

And for those who are extra keen, here's my Quirks & Quarks radio interview from January 2014.

Paleo201 comes to an end

The first offering of Paleo201, Dinosaurs in the Fossil Record, essentially comes to an end today with the final field trip of the semester. The students will have their exam later in December.

Even though it is a lot of work to be involved in the creation of a new course, I think Paleo201 is a great addition to the University of Alberta's paleontology offerings. Using the Dino101 content on Coursera, and pitched at an essentially first-year level (despite its 200 designation) for students from all faculties, Paleo201 is what's called a blended learning course. We rely on the Dino101 course videos to deliver the base lecture content for the course, which means we typically only meet once per week for an in-class lesson. These lessons have included research talks by grad students in our labs on topics relevant to each week's lesson. However, we also tried to break away from the lecture format for at least some of the in class lessons, to take advantage of some of the resources available on campus. One week we learned the basics of the rock cycle and general Canadian geology using the Department of Earth and Atmospheric Sciences Geoscience Garden, an installation of rocks from around Canada arranged in a particular fashion for students to learn basic mapping skills. And last week we did tours of the Paleontology Museum and our prep labs, including sneak peeks of some cool up and coming research projects. FUN FACT: Our Dunkleosteus skull cast was ranked higher than the dinosaur specimens in my highly scientific 'what did you find most interesting' poll. Blindingly obvious take-home message for instructors: Students like new things and surprises, and dinosaurs are not necessarily the be-all and end-all!

But the highlights, in my opinion, are the three field trips to Jurassic Forest, Dry Island Buffalo Jump Provincial Park, and the Royal Tyrrell Museum.

Jurassic Forest is a tourist attraction outside of Edmonton that features animatronic dinosaurs set outside in a forest. Although I had some comments that this was an odd place to take students on a university field trip, I actually think it worked really well as a way to ease students into some of the topics covered in the first couple of lessons – basic dinosaur anatomy, diversity, diet, etc. And because a lot of the signage and interpretive material at the forest has been put together by graduates of the UofA's BSc program in Paleontology, the educational content is accurate, up to date, and nicely presented.

Many of the students told me that our trip to Dry Island was the first time they had really gone hiking, so I think that speaks to the value of having a course like this one. We hiked the students around the badlands and out to the Albertosaurus bonebed, stopping to discuss  geology, look for fossils (but not collect any, as we didn't have permits this time), and talk about how we interpret bonebeds and make inferences about dinosaur behaviour. Everyone was SO EXCITED to find little bits and fragments of bones. A couple of the students told me they returned the next weekend with their families because they had enjoyed the field trip so much! Blindingly obvious take-home message for instructors: Students like to go outside! And while videos and online stuff and lectures are perfectly fine, doing 'real' things with real fossils and real locations etc. etc. can never fully replace the online experience. Also I got artists and history students and linguistics majors and such to like rocks, so there.

And today we headed down to the Tyrrell Museum, which is a bit of a long day trip from Edmonton, since Drumheller is a little more than 3 hours away – but we were helped along by some dino documentaries. As always, the museum is an amazing resource, and it was super fun to see the students putting together many of the different concepts learned this semester. There were many good questions and enthusiastic discussions about the things we were seeing. And of course, having Phil there to talk to the students about the history of the museum and some of his personal experiences in collecting many of the fossils on display is pretty cool!

Because this is partly an online course, one of the things I've tried to incorporate into the field trips is discussion of the field trip in the course discussion forums. Each time the students have had to take a picture of themselves with a backdrop of choice (favourite dinosaur at Jurassic Forest, favourite scenic view at Dry Island, favourite display at the Tyrrell) and tell us something about it. This worked really well and it is also a fun way to get some feedback about what people are twigging onto as interesting in the course. Fun fact: Not everyone's favourite dinosaur/etc. was T. rex! There is hope for the world!

This is the last course for which I will ever be a teaching assistant, as my grad school days are wrapping up in a few weeks. This course was lots of fun to teach, hopefully has been fun to take, and I hope future students and instructors have as much fun as I did!

You're Invited!

The University of Alberta Laboratory for Vertebrate Paleontology is celebrating the 50th anniversary of a landmark international paleontology conference, held at the university in 1963 and which kicked off the start of our formal paleontology program here, with a symposium on Friday, August 30.

You're invited to join us in Edmonton from August 29 to September 1. Our 50th anniversary celebrations will be held concurrently with the 2013 Canadian Paleontology Conference, and the inaugural meeting of the Canadian Society of Vertebrate Paleontology.

Abstracts for the CPC are due by August 1. You can register for both events, and find out more information, at our conference website: http://cpc2013.wordpress.com.

We hope that many of our palaeontology colleagues, and especially UALVP alumni, will be able to join us in Edmonton in August!

Who-oplocephalus: The Fellowship of the Half Ring

Behold, NHMUK R5161: the extraordinary holotype of Scolosaurus cutleri. This is truly one of the most amazing dinosaur fossils that has been collected from Alberta, and is one of the best preserved ankylosaurs in the world. And the best part is that it is on display for everyone to enjoy in the galleries of the Natural History Museum in London.

(Many thanks to Angelica Torices for snapping this photo for me! NHMUK R5161 is beautiful to look at, but difficult to photograph well, and I'm afraid most of my photos from my visit in 2009, while useful to me, are not necessarily that nice to look at.)

Most of the time, when you're looking at a drawing or model of Euoplocephalus, what you're really mostly looking at is NHMUK R5161. This specimen preserves a large amount of intact skin, which means that the free-floating osteoderms are, for the most part, in their correct life positions. Osteoderms form in the dermis of the skin, and so osteoderms are usually found as isolated elements, or scattered around disarticulated or associated skeletons. Because NHMUK R5161 is so complete, it has formed the basis for most restorations of Euoplocephalus.

Yup, all of these are kind of Scolosaurus. Especially the pink one. Perhaps somewhat embarassingly, this does not represent my complete collection of ankylosaur 'scientific models'.

However, you may have noticed something important: Scolosaurus lacks a skull and tail club. So, how could I figure out if Scolosaurus was the same as Euoplocephalus, if I couldn't look at the patterns of cranial ornamentation? If you remember back to part 2 of this series, I said that the morphology of the first cervical half ring was useful for diagnosing Euoplocephalus. 

The first cervical half ring of NHMUK R5161 has some important differences when compared to CMN 0210, UALVP 31, or AMNH 5406. In NHMUK R5161, the two medial osteoderms (closest to the midline) are round and lack keels, instead having a centrally located bump. Even in specimens of Euoplocephalus that have relatively flat medial osteoderms on the cervical half rings, like AMNH 5404, the medial osteoderms always have a keel and are more oval than circular. This suggested that Scolosaurus was distinct from Euoplocephalus and Anodontosaurus, even though it didn't have a head or tail club. (I largely agree with Penkalski and Blows' (2013) assessment that Scolosaurus is a valid taxon, but for somewhat different reasons than what they present in their paper.)

This reconstruction of Scolosaurus was drawn by Alice Woodward based on NHMUK R5161, and I suspect that many subsequent images of Scolosaurus were inspired by Woodward's art.

(A quick note about tail clubs and Scolosaurus – many artists have reconstructed this animal with a short tail and spiked tail club. The tail of NHMUK R5161 is broken at about the midpoint of the tail, probably just in front of where the tail club would have started. The skin is kind of sloughed out in this area, which has led many to erroneously interpret Nopcsa's figures and drawings as showing the knob of bone at the end of the tail. The 'spikes' on the tail club are really just osteoderms present at about the midpoint of the tail – no ankylosaurs had spikes on their tail clubs.)

The collection of NHMUK R5161 is one of the more interesting stories of palaeontological collecting in Alberta. The specimen was discovered and primarily excavated by William Edward Cutler in 1914, working for the Calgary Syndicate for Prehistoric Research (an excellent name for an organization that is, sadly, defunct). During excavation, the ankylosaur block collapsed on Cutler, no doubt causing grievous injuries. One of the Sternbergs finished the excavation, and the specimen was shipped to London.

NHMUK R5161 is significant, beyond being so complete, because it may derive from the Oldman Formation of Dinosaur Provincial Park, rather than the Dinosaur Park Formation. The quarry is somewhere across the river from Happy Jack's, the University of Alberta's field camp since 2008. However, the precise locality of the quarry is somewhat up for debate, and Oldman Formation sediments crop out in this area. Next week I'll be heading to Dinosaur Provincial Park, and one of the goals is to check out some of the potential quarry locations with our crew from the UofA, as well as Darren Tanke from the Tyrrell Museum, who has been investigating the NHMUK R5161 quarry for some time. It's important to know whether or not Scolosaurus comes from the Oldman or Dinosaur Park formation, so we can know whether or not Scolosaurus lived at the same time as Euoplocephalus. We will also be on the lookout for any leftover material…like the skull and tail club.

Two Medicine Formation skulls, from Arbour and Currie (2013). Notice the long, curved squamosal horns.

For a long time I was bitterly disappointed that there was no skull known for Scolosaurus. Could some of the isolated skulls I was referring to Euoplocephalus instead belong to Scolosaurus? Or was the skull of Scolosaurus noticeably different from Euoplocephalus? I despaired that I wouldn't have an answer to that question unless we miraculously collected another Scolosaurus from Dinosaur Park during my thesis. In the meantime, I was trying to figure out the identities of "Euoplocephalus" specimens from the Two Medicine Formation of Montana, which seemed very different from the Albertan specimens. These skulls had much longer and pointier squamosal horns with a 'backswept' appearance compared to Euoplocephalus and Anodontosaurus. I thought perhaps that the Two Medicine ankylosaurids might represent a new species of ankylosaurid (as did others – Penkalski named Oohkotokia earlier this year based on MOR 433, which has this unusual squamosal horn morphology).

From left to right, the first cervical half rings of AMNH 5337, TMP 2001.42.9, USNM 7943, and NHMUK R5161. The top row shows the half rings in anterior or posterior view, and the bottom row shows the rings in dorsal view. NHMUK R5161 is in dorsal view. Modified from Arbour and Currie (2013).

One day I was flipping through my photos of the Two Medicine Formation specimens when I realized that the morphology of the first cervical half ring of TMP 2001.42.9, the only specimen that had a half ring and skull, matched that of NHMUK R5161. Both had flat medial osteoderms with a central bump, rather than a keel. And indeed, another isolated half ring from the Two Medicine formation had this morphology as well. Scolosaurus was present in Montana!

I'll just take a moment here to address Oohkotokia: while I agree with Penkalski (2013) that the Two Medicine Formation ankylosaurid differs from Euoplocephalus, I do not think it differs sufficiently from Scolosaurus for these to be considered separate species. Perhaps one day in the future we'll find another Scolosaurus from Dinosaur Park that has flat medial osteoderms on the cervical half ring, but a skull with different squamosal horns compared to the Two Medicine skulls. If that happens, then I think you could make the case that Oohkotokia is valid. Until then, Oohkotokia is a junior synonym of Scolosaurus.

With the referral of the Two Medicine ankylosaur material to Scolosaurus, Scolosaurus now had a head! TMP 2001.42.9 even has a tail club, so we know that Scolosaurus had a round tail club knob. With the in situ osteoderms and skin impressions of NHMUK R5161, Scolosaurus is now one of the best understood ankylosaurids in the world. Now, if we could just figure out for certain exactly where it was collected from…

Next time: wrapping up loose ends, and figuring out what it all means.




PAPERS!


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

Nopcsa BF. 1928. Palaeontological notes on reptiles. V. On the skull of the Upper Cretaceous dinosaur Euoplocephalus. Geologica Hungarica, Series Palaeontologica 1:1-84.

Penkalski P, Blows WT. 2013. Scolosaurus cutleri (Ornithischia: Ankylosauria) from the Upper Cretaceous Dinosaur Park Formation of Alberta, Canada. Canadian Journal of Earth Sciences 50:171-182.

Penkalski P. 2013. A new ankylosaurid from the Late Cretaceous Two Medicine Formation of Montana, USA. Acta Palaeontologica Polonica, in press.

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 museum for 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.

AND HERE ARE SOME PAPERS!

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.