Wednesday, April 9, 2014

Nitpicking Euoplocephalus

A friend of mine posted this amazing video on Facebook, and I must share it!



I really like how the Geek Group have obviously put a lot of time into researching the anatomy of the dinosaurs they're featuring, and the stylized animations are super cool. I'm obviously biased towards this episode, but I'm looking forward to seeing more!

For those who are interested in learning more about the anatomy of Euoplocephalus, may I offer these blog posts?:

Baron von Nopcsa, Scolosaurus, and the spiky-clubbed ankylosaur.

You can pick your friends, and you can pick your nose...and you can definitely pick your ankylosaur's nose.

Who-oplocephalus
Who-oplocephalus: Is Euoplocephalus 'real'?
Who-oplocephalus: Heads for tails.
Who-oplocephalus: The Fellowship of the Half Ring
Who-oplocephalus: Everything old is new again.

Scaling up


And for the keeners, you can also check out a lecture I did for the Royal Tyrrell Museum's lecture series via their YouTube page!





Bonus: The Dinosaur Toy Blog also enjoys nitpicking the accuracy of dinosaur toys!

Saturday, April 5, 2014

Name that Specimen, Canadian Museum of Nature edition

I haven't done one of these for a while! See if you can guess what specimen is which!

1.

2.

3.

4.

5.

























 1. It's spiky side up for this Styracosaurus!
2. Here's the shovel-beaked maw of a hadrosaur.
3. Don't get too close to the business end of an ankylosaurid – the tail club can pack a wallop!
4. Did you guess Edmontosaurus? Here's the pelvic girdle of this iconic hadrosaur.
5. The reconstructed skin of Vagaceratops is very colourful!

Wednesday, April 2, 2014

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!


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

Sunday, March 30, 2014

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.

Sunday, December 8, 2013

Back to Hwaseong

This week I've been in Hwaseong city, Korea for the HwaseongInternational Dinosaurs Expedition Symposium. I started this blog back in 2010 as a way to document my experiences working in the dino lab in Hwaseong, and so it was wonderful to be able to return more than three years later and see what's new. The symposium highlights research following the conclusion of the five-year Korea-Mongolia International Dinosaur Project. Many thanks to Dr. Yuong-Nam Lee, the city of Hwaseong, and all of the other organizers and staff who invited us to present our work at this excellent conference!

 
It was a special treat to see the new ankylosaur skeleton prepared and mounted in the lobby of our hotel! Watch out Tarbosaurus, you're about to get a face full of tail club.

Outside the main event room, the city had set up the winning entries from a local crafts contest themed around Koreaceratops. There were some awesome items on display!

It was also wonderful to eat real Korean food again! So tasty.

Hwaseong is home to dinosaur nesting sites as well as the holotype of Koreaceratops. There's a new observation tower on the hill above the reclaimed salt marsh which gives an excellent view of the area. The islands in the midground are Cretaceous egg-bearing rocks, but apparently the hill we're on in this photo, and the hills in the distances, are Precambrian basement.

Heading on out to see some of the nests!

The outside of the visitor centre has undergone a dramatic transformation, and now hosts a gigantic bas relief of Julius Csotonyi's Koreaceratops illustration.

Koreaceratops has also replaced the old Protoceratops model inside the centre. We also had a chance to check out some really special specimens collected during the expeditions that have now been prepared, but they are secret until published, so I can't share photos here! Needless to say, there are some wonderful papers coming down the pipeline resulting from these expeditions. On to the next adventure!

Saturday, November 30, 2013

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!

Saturday, November 16, 2013

SVP Report 3: the Page Museum


For the final entry in this year's SVP recap, let's head over to the Page Museum, which showcases specimens collected right outside its front doors in the La Brea tar seeps.


So many specimens have been collected from the tar seeps that the museum has over 400 dire wolf skulls on display - out of more than 1500 in their collections! It makes for an impressive Wall of Stuff. I am envious of their actual non-negligible sample size!


A dire wolf skeleton with a baculum! Now there's something you don't see every day!


I love surprises in museums! I'm used to seeing Panthera atrox, the large cat skeleton in this photo, labeled as the American lion, but here it was called Naegele's giant jaguar! Turns out there's been some back-and-forth about whether or not Panthera atrox is more lion-like or more jaguar-like; recent research seems to put it in the lion lineage. Whether or not the cat is a lion or a jaguar has some interesting biogeographical implications! P. atrox is a relatively rare component of the La Brea deposits compared to dire wolves and sabercats.


Giant not-condor says hi! HI TERATORNIS!


I'm sure I'm not the first to say this, but man, ground sloth feet are weird.


In addition to all of the lovely large skeletal mounts, there's a very nice wall showcasing some of the smaller fossils, and things like taphonomy and pathology. Here's a cool example of rodent gnaw marks on a bone!


And here are the fused foot bones of a Smilodon! Ouch! 


There's a really excellent fishbowl lab - nobody working there when I visited, since it was a Sunday, but it looks like a pretty busy place with lots on the go!


I also liked how they made it so you could see into the collections area!


Finally, I'll end with this adorably retro display on the process of cataloguing and curating fossils (which I am totally happy to see in a museum exhibit)...featuring punch cards.