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It's #SciArt week on Twitter!

March 3, 2015, 4:25 pm
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I think we often downplay or take for granted the role that art plays in science. High quality art is obviously a hugely important aspect of public science communication. A paper describing a new species of dinosaur will have much more impact on the public if it's accompanied by an excellent life restoration of that dinosaur. Astronomers and their spacey kin use illustrations to show us satellites, the solar system, and far-off planets we can't photograph. Biologists dealing with the very small need illustrators to show us the cells in our bodies, what's inside those cells, what DNA looks like and how it works – the list is endless.

But the #SciArt tweet storm happening this week got me thinking again about the role that art plays in my own daily scientific activities. While I don't consider myself an artist, I was always drawing while I was growing up (for a while I entertained the idea of becoming an animator!). And I'm still drawing! Every time I go to a museum, I draw pretty much everything I look at. Why draw when I've got easy access to digital photography? Well, I take tons of photos, too, but drawing makes me LOOK at the specimen. 

LOOKING AROUND YOU IS VERY IMPORTANT.


Sketching slows me down, in a good way. What's that weird texture in this part of the bone, how far does this groove extend, what's with this unusual hole in this spot? Is there symmetry? Asymmetry? What's missing, and what's been filled in with plaster? What exactly was I measuring when I say 'length' or 'width'? I've filled many notebooks with drawings, stream-of-consciousness-style notes, measurements, and other bits of data. Mostly I use regular ol' pencils, but I also really like coloured pens and usually travel with a set for annotating my pencil drawings. I would love to be the kind of person that could do watercolour sketching, or proper graphite drawings.

These are some of my earliest notes from my MSc research, from a 2007 visit to the Royal Ontario Museum.


I think, as scientists, we do ourselves a disservice by not teaching students more about art skills and visual design. Being able to quickly and confidently sketch something in front of you is a useful skill to have! And understanding some of the principles of visual design – lines, shapes, negative space, colour combinations, and the like – can only make you a better communicator of science, especially in scientific papers. In addition to just being personally rewarding, drawing makes me a better scientist!

If you're a Twitterer, you should really check out the #SciArt hashtag this week (and into the future), to see the variety of techniques and approaches people take to science art. 
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What's up at Wapiti River?

March 24, 2015, 6:25 pm
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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.
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#MuseumWeek Retrospective!

April 1, 2015, 5:44 pm
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Last week's #MuseumWeek tweetstorm was an awful lot of fun, especially following the #SciArt event just a few weeks earlier. I thought I'd share a couple of photos and thoughts for each day's theme – I didn't manage to post something for each day on Twitter, but I'll fill in some thoughts and photos here!

Day 1: Secrets
One of the nice things about working in the Paleontology & Geology Research Lab at the North Carolina Musuem of Natural Sciences is that "behind the scenes" is part of the scene. You can actually stare at me while I'm working away at my computer each day, if you desire to do such a thing. More interesting, probably, would be to watch our staff, students, and volunteers preparing fossils in the main lab space - secrets waiting to be revealed. But hey, whatever floats your boat!

If you're in Raleigh, stop by and say hi to Carnufex!


Day 2: Souvenirs
I am kind of a Stuff Person and also have a Thing for Museum Gift Shops. As such, I have loads of doodads from my various museum visits. One of the things I like picking up are postcards, especially those that have non-Tyrannosaurus dinosaurs featured on them. For a while, I had these up on my wall at my apartment in Edmonton. Those who have visited my UofA office will also be familiar with my embarassingly large collection of ankylosaur toys, or as I prefer to refer to them, 'scientific models for grown-ups'.

Recognize any museums from your own travels?


Day 3: Architecture
I had a lot of fun with this one on twitter because I LOVE interesting museum architecture. A couple of favourites:

Permian Hall at the Moscow Paleontological Museum:

...which also had custom door hinges, like plesiosaurs!

Dinosaur museum in an old castle in Lerici, Italy:


I wasn't sure about the ROM Crystal at first, but it's grown on me:

And I think the SECU Daily Planet at the NC Museum is pretty swell (on the inside, it's a theatre!):



Day 4: Inspiration
Some non-dinosaur stuff for inspiration day: I really like learning about Canadian art and its history, and one of my very favourite museums on the entire planet is the Museum of Anthropology at the University of British Columbia. If you're in Vancouver, DO NOT MISS THAT MUSEUM. It's an emotional experience to step into the exhibits at this museum and be surrounded by so much creativity and history and skill. Here's a sample to sharpen your brain.





Day 5: Family
I'm lucky to have had great parents that fed my dinosaur obsession as a kid with trips to museums near and far. I'd love to dig out some photos from the before time, but for now, I'll leave this day for my own memories. What are some of your favourite museum memories from your childhood?

Day 6: Favourites
I like busy museums that are crammed full of stuff, especially when that takes the form of a Wall of Stuff or a Hall of Stuff. Here's a few of my favourites.

Hall of Stuff at the Museo de La Plata

Wall of Stuff at the Natural History Museum of LA County

Day 7: Pose

I don't like posting pictures of myself very much, so I'll just include one here to finish off: here's Pinacosaurus (nee "Syrmosaurus") at the museum in Moscow, with me for scale.



That's it for now! What did you share for Museum Week?
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A Brontobyte of Sauropods

April 7, 2015, 5:06 am
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Palaeontology emergency alert! This is not a drill! Brontosaurus is back!

YES I FINALLY GOT TO USE THIS ON THE BLOG. Success!


I mean, Brontosaurus never really left. That's the nice thing about taxonomy – once a name is out there, it's there forever, even if we decide later on that it might represent the same kind of animal that another name does. And so every now and then, we get to bring an old name back from the dead. Today, Tschopp and colleagues have published some very good support to indicate that Brontosaurus really is distinct from Apatosaurus after all, and we can all use that name and stop telling people that Brontosaurus isn't real. OMG, WHAT A RELIEF. 

To recap: Brontosaurus has not been an accepted name in the palaeontological community for more than 100 years, but because of its use in some museum exhibits, and things like the 1964 World's Fair and the "Rite of Spring" passage in Fantasia, for example, the name has become entrenched in the popular consciousness in a way few other dinosaur names have. It is very disappointing to learn that palaeontologists don't call that big dinosaur Brontosaurus, but the decidedly less evocative name Apatosaurus instead.

Click for sauropod-size. With many thanks to the authors and PeerJ for creating such a useful diagram, which I'm sure will be reproduced often and with much gratitude by palaeontologists, teachers, and other science communicators.


The new paper is staggering in its length (almost 300 pages!) and the amount of work it represents, and I'm not a sauropod specialist, so I'll summarize it here without delving into sauropod anatomy very much:
Two of the Big 3 diplodocids: Apatosaurus (in the back) and Diplodocus (foreground) face-off at the Carnegie Museum.

  1. Tschopp et al. did a specimen-level phylogeny of diplodocids, the sauropods like Apatosaurus and Diplodocus, but not Brachiosaurus or Camarasaurus. This means that individual specimens were coded, rather than species. Often, phylogenetic studies have just looked at the 'classic' diplodocids Apatosaurus, Barosaurus, and Diplodocus (the 'Big 3', shall we say?). And most of those studies elide the many species represented by these three genera. So a specimen-level phylogeny is a much-needed approach to resolve some questions about diplodocid diversity.
  2. They then used some techniques to quantify differences among specimens – pairwise dissimilarity, and apomorphy counts – that would help justify dividing clusters of individuals into different genera. There isn't a rule in palaeontology that individuals need to be a certain amount 'different' from each other in order to be a new genus or species, so the authors looked at how many unique characters separate some sauropods that everyone seems pretty comfortable calling different species and genera. Apatosaurus ajax and Apatosaurus louisae had 12 different features, and Diplodocus carnegii and Diplodocus hallorum had 11 different features. So 13 different characters was set as the baseline for separating out genera in the specimen phylogeny. Using the same approach, they also set 6 differences as the baseline for separating species within a given genus. These numbers only apply to this particular analysis, but it's an interesting approach that I think would be worth considering for other dinosaur phylogenies.
  3. Using this, they wind up doing some taxonomic reshuffling:

a.       Diplodocus longus lacks any diagnostic features at the species level and is a nomen dubium, which is bad because it's also the type species for Diplodocus. A petition to the ICZN to switch the type species to D. carnegii is in the works. Diplodocus includes the species D. carnegii and D. hallorum (née Seismosaurus)
b.      Dinheirosaurus (from Portugal) is a junior synonym of Supersaurus, and so Supersaurus is a cross-continental genus represented by two species.
c.       Diplodocus hayi passes the threshold for generic distinctiveness from Diplodocus and gets a new name, Galeamopus hayi. Specimens of Galeamopus are actually more complete than Diplodocus, which means that Diplodocidae is best represented by Galeamopus at present if you need a diplodocid for whatever you're working on.
d.      And finally, and arguably most significantly, Brontosaurus passes the threshold for generic distinctiveness from Apatosaurus. There are three species within Brontosaurus: B. exelsus ('classic'Brontosaurus), B. parvus(née Elosaurus), and B. yahnahpin (née 'Eobrontosaurus').


The third of the Big 3 diplodocids, the iconic rearing Barosaurus at the American Museum of Natural History.


I really hope this taxonomic shuffling gains wide acceptance, because 1) I think their approach and reasoning are pretty sound, and 2) it's going to be SO MUCH EASIER not to have to constantly 'debunk'Brontosaurus with non-palaeontologists.The oft-repeated story that "Brontosaurus" wasn't real because it had the head of one animal and the body of another is wrong, but the real story, about the rules of taxonomy and how we define species, is much more difficult to explain. (It's interesting, but it's not as easily parsed to a lay audience.) And let's face it, Brontosaurus was a really good name and it was sad that it had to be synonymized. The story of Brontosaurus now has a new and interesting chapter – our ideas about the biology of Brontosaurus have changed, but now we can talk about changes to how we think Brontosaurus looked and lived, rather than just focusing on a quirk of taxonomy. So let your Brontosaurus flag fly high, dinosaur fans, because Brontosaurus is back and that's awesome.

Old-timey sauropod in the little diorama at the Smithsonian, back in 2011.

Big taxonomic revisions are hard and important but often don't feel as 'sexy' as some of the other research that gets publicized. I like thinking about alpha taxonomy (uh, perhaps obviously) and I like doing this kind of research, and I think it's really important that we recognize how important this kind of work is – alpha taxonomy is really foundational to a lot of other studies. If you don't know how many species you have, or where they lived, or what anatomy belongs with each species, how can you do projects that look at the evolution of certain features through time, or understand changing ecosystems? 

For example, given that there's at least 14 species of diplodocid in only 11 million years of Morrison Formation, it's unlikely that there's a slice of time in there in which there's only one diplodocid species. (And remember, diplodocids weren't the only sauropods in the Morrison – this is also the home of Brachiosaurus and Camarasaurus and Suuwassea and who knows what else.) This is a pretty good reason to reject what I like to call the "Highlander hypothesis", i.e. There Can Only Be One ___(ankylosaur, tyrannosaur, whatever)___ in a given formation, something that I've encountered in conversations on occasion. It's understandable that we would feel unease at the idea of high species/generic diversity in such massive dinosaurs, because how are they dividing up ecosystem space? But over and over again it seems like lots of similarly-shaped dinosaurs were occupying similar times and spaces in terms of what we see in the rock record, which I find very interesting indeed. (Now what we need is a really good stratigraphic framework for putting all of these diplodocids into chronological and geographical context.) We can only do a good job of addressing these kinds of questions by having good data to put into those studies, and that data comes from taxonomic revisions like this one.

And revising taxonomy is probably a never-ending job, because we need to keep reassessing our definitions of genera and species as we get more information through new specimens. Let's make sure we all support this kind of research as palaeontology continues to evolve with new techniques, questions, and approaches. Bully for Brontosaurus, and bully for alpha taxonomy.


Stray observations:
  • The concept of a 'relatively small' animal that is 12-15 metres long amuses me. (re: Kaatedocus, page 2)
  • The 'brontobyte' image at the top of this post is an old joke from my Currie lab days; a brontobyte is actually 10^27 bytes. But I think it would be a good collective noun for sauropods, and it also feels appropriate given the large number of sauropod species recovered by Tschopp et al. In fact, we need more collective nouns for dinosaurs, and so I'd like to propose brontobyte for sauropods and armada for ankylosaurs, to join terror of tyrannosaurs.


Go read the paper! It's open access!: Tschopp E, Mateus O, Benson RBJ. 2015. A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda). PeerJ 3:857.

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May your mountains dark and dreary be.

April 27, 2015, 9:04 pm
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Just wanted to give a quick shout out to some old fossil friends of mine. Horton Bluff/Blue Beach is a pretty cool place and I have fond memories of field trips out there during my Dalhousie days. Between this new paper and the recent paper describing the Permian to Jurassic assemblage of tetrapods, it's been a good time for Nova Scotia palaeontology.

Your friendly neighbourhood ankylosaur palaeontologist, in the before time (i.e. 2003), at Horton Bluff, following in her tetrapod ancestor's footprints. It's goopy there.




Which of course makes me miss it all terribly.



Anderson JS, Smithson T, Mansky CF, Meyer T, Clack J. 2015. A diverse tetrapod fauna at the base of 'Romer's Gap'. PLOS ONE 10:e0125446.

Sues H-D, Olsen PE. 2015. Stratigraphic and temporal context and faunal diversity of Permian-Jurassic continental tetrapod assemblages from the Fundy rift basin, eastern Canada. Atlantic Geology 51:139-205.
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On Surprises

May 5, 2015, 6:10 pm
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I love surprises. Which is unfortunate for me, because I am extremely bad at being surprised. And it's hard to be surprised by things as you get older, and as easier access to more and more information becomes available to us every day.

But boy, when a surprise comes along that actually takes me by surprise, what a thing to be able to savour.


An extraordinary painting of Yi qi by Emily Willoughby, CC-BY.

So, enter Yi qi. In many ways, it's hardly a surprise at all – numerous artists produced wonderful speculative art about scansoriopterygids predicting membranous wings and/or gliding abilities, and there was even this neat hypothetical Archaeopteryx ancestor that I found in a paper a few years ago. At the time, I wrote on Facebook: "I had not realized that a bat-winged proto-bird was an idea that was on the table!"

(I also wrote, "I like his smirk, lack of neck, and skinny skinny tail", and I agree with Past Victoria about all of those things.)

While Yi qimight not really be a proto-bird, it's still an amazing discovery that shows there was a lot of experimenting with flying and gliding going on back in the Mesozoic, which is perhaps unsurprising, given that lots of disparate groups of animals use gliding to their advantage today – fish, frogs, rodents, marsupials, dermopterans, you name it. And yet, even though there's lots of precedent for gliding vertebrates, and others had predicted something kind of like Yi qibefore, I was still genuinely shocked when I saw the paper and press images. What a great feeling.

What I love best about Yi qi, apart from it's extremely meme-able name, is that it's a great example of maybe what I'll call an 'expected surprise'. A surprise that, as soon as you see it, it seems so obvious and like it should have been there all along. It's like the opposite of a failure of imagination. Surely there is a long German word that captures this specific emotion? What other expected surprises are lurking out there in our futures? What things have we speculated on today, dismissed as being way too out there to take seriously, and yet will pop up as really-for-real things later on?


I guess I need to get to work on some ankylosaur speculative biology! Maybe we'll find the real Yee?

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On Failures of Imagination

May 6, 2015, 4:43 pm
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Yesterday I talked about 'expected surprises' with regards to Yi qi. Yi qi is a surprise because its anatomy is so unlike other theropods, and it suggests that dinosaurs were experimenting with flight and/or gliding in some ways that were quite different from our current understanding of feather and bird wing evolution. But it was also not entirely unexpected, because scansoriopterygids had super weird anatomy to begin with that gave us enough information to speculate about possible gliding adaptations in those dinosaurs, even though the general consensus was that it was pretty far-fetched.

But today I wanted to talk about a related feeling, which I like to call the Failure of Imagination. Last summer I was working my way through a DVD set of classic sci-fi, fantasy, and adventure movies that I had picked up at some point. I wound up watching a lot of these with friends and basically Mystery Science Theatre 3000-ing the films, and in particular the old space adventure movies from the 40s-60s provided much entertainment. It's really fun to take a look back and see what sorts of things people envisioned the future holding for us – space travel, exoplanet exploration, robots. But what also struck me was the things that the filmmakers and storywriters couldn't even imagine. 

They could imagine spaceships and robots, but they couldn't imagine wireless technology. Or storing information in digital form rather than on spools of tape. 
Voyage to the Prehistoric Planet (1965) 

They couldn't imagine non-button-and-dial-based instrumentation. 
Rocky Jones, Space Ranger: Crash of Moons (1954)

And they definitely couldn't imagine women in roles other than administrative assistants (or as the bad guys). SO MANY SPACE SECRETARIES.


I kept thinking to myself – what sorts of failures of imagination are we having in palaeontology today? We can imagine so many things. But I wonder what kinds of things we won't even know we don't know. When we try our hand at speculative biology, what will scientists 80 or 100 years from now think was charming, or quaint, or ahead of its time. Failures of imagination are one of those things that make me nervous as a scientist, because I don't like the idea that I won't even know what I'm not imagining.
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Crystal Geyser Quarry Quest

June 1, 2015, 7:52 pm
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I just got back from my first stint of fieldwork for the year, and my first time doing fieldwork in the States. This was just a brief jaunt out to Utah and Colorado for two weeks, but it was a nice sampling of some interesting and different field localities compared to my previous experiences. Today's post: Crystal Geyser quarry in Utah!

So scenic, so majestic. Such altitude.


Crystal Geyser is a non-geothermal, carbon dioxide geyser near Green River, Utah; although we didn't visit the geyser itself, it lends its name to a series of quarries of a massive bonebed in the Yellow Cat Member of the Cedar Mountain Formation (about 125 million years ago). The bonebed is mostly composed of the early therizinosaur Falcarius. The bones in this quarry are incredibly delicate - sometimes even using just a brush through the sediment felt like it was too aggressive! Definitely a challenging site to work at.




Ominous clouds brewed up frequently and then dumped rain and hail on us.


But then sometimes there were rainbows, so I guess it was ok.


We camped in the Morrison Formation and walked up to the Cedar Mountain Formation each day, which was kind of fun.

I'm not accustomed to walking through such a dramatic shift in time and faunas: the Morrison is characterized by lots of classic dinosaurs like Allosaurus and Apatosaurus and Stegosaurus from about 156 to 146 million years ago, but the dinosaurs of the Cedar Mountain Formation have only recently begun to receive much attention and are still poorly known. There's a gap of about 20 million years between the two formations, and in the Yellow Cat Member we find dinosaurs like Falcarius, the ankylosaur Gastonia, the iguanodontians Hippodraco and Iguanacolossus, and dromaeosaurs like Utahraptor and Geminiraptor. The world was changing.

We'll be returning to Utah later in July to work in the Mussentuchit Member. Up next: jackhammering in the Mesaverde Formation of Colorado!

Epilogue: I made a friend at lunchtime one day. D-:
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Mad Max: Fury Quarry

June 3, 2015, 6:55 pm
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There's a hadrosaur underneath this cliff. (Probably.)

For the second week of our field expedition, we drove from Utah to a site near Rangely, Colorado, to help the Colorado Northwestern Community College with a specimen poking out of a cliff. We've shifted into the Upper Cretaceous here, and are working in the Mesaverde Formation. There's not very much known about the dinosaurs from this formation, so hopefully this will shed some more light on the dinosaurs in this region!



In between Utah and Rangely, we spent a night in Grand Junction and went to see Mad Max: Fury Road, which was way more awesome than any of us had really anticipated and which was basically all we could talk about all week. And so I must also share this great photo that Lindsay took! According to buzzfeed, my Mad Max name is Roop Duststorm, which seems appropriate given the dustiness of working around a rock saw all day.



I did a lot of jackhammering last week, which was great fun if terrible for my lower back, but my favourite thing to do is to pop off the blocks made using the rock saw. You cut a grid into the rock, position your chisel at just the right point, give a couple of hearty whacks with a crack hammer, and off pop these incredibly satisfying 'brownies' of sandstone. It's still slow going, but you can move a lot of rock a lot more quickly this way. (Thanks to Lindsay again for snapping this fun photo!)



Early in the week we were plagued with constant large thunderstorms that rolled in every few hours and made things kind of cold and miserable. Thankfully, this was the last one and it missed us! Instead, it just looked dramatic, which is fine by me.


By last Saturday we had made a lot of progress, although there is still a long way to go to get down to the bone level and (hopefully) find a good dinosaur down there. Best of luck to the crew as they keep working furiously away!



*'Fury Quarry' is also shamelessly stolen from Lindsay.
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Cornelius says hello

June 13, 2015, 4:19 pm
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Say hello to Cornelius! I got to meet him during a brief visit to the ROM last week, and he seems like a pretty nice guy.

This cool new ceratopsian is on display in the Age of Dinosaurs gallery in an exhibit called "New Dino Discovered", and was also featured in Dino Hunt Canada, which aired earlier this year. It should have a new name soon, but for now Canada voted to nickname it Cornelius. The really nice skeletal mount was put together by Research Casting International based on about a 50% complete disarticulated skeleton.

Here's a close-up of that winning smile. This new dude is a centrosaurine ceratopsid with some pretty neat ornamentation going on at the back of the frill.

I really liked the inclusion of a quarry map on the floor, which highlights some of the bones that are on display. The skeleton was found in southern Alberta in the Milk River area, and comes from the Oldman Formation.

The mounted skeleton is a cast, but there are some original bones on display, like the radius and ulna shown here.
 
In particular, I liked this set of panels on the wall showing differences in frill ornamentation between centrosaurines, and how we identify different species. On the right is the original frill material for Cornelius, the bottom left is Centrosaurus, and the top left is Styracosaurus.

And look, there was even an ankylosaur osteoderm on display! These are some of the fossils found in the Milk River area, which tell us a bit about the ecosystem that the new centrosaurine lived in.

It's a cool new dinosaur and a nice exhibit, so definitely don't miss it if you're visiting the ROM anytime soon!
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Why does Jurassic World hate dinosaurs?

June 16, 2015, 8:35 am
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I have some Thoughts and Feelings about Jurassic World! Spoiler alert, I'm going to talk about details and plot points and this post is really for people who have seen the film. Also, while I'm going to talk about the dinosaurs a bit, this isn't really a review of the science of the film, because that's already been done to death. Ok, onwards and upwards into something that wound up being way too long!



Does Jurassic World hate dinosaurs?

I think the answer to that question is yes. Jurassic World keeps making these little homages and throwbacks to the earlier films (there are lots of shots that echo iconic moments in the earlier films, and some of the plot points mirror the original film almost exactly), and yet I feel like we could consider the theme of Jurassic World to be about rejecting nostalgia and childhood. It's buried under an interesting discussion of the role of the military in funding scientific research, and why some kinds of research are prioritized over others, and it may actually be unintentional, but it's the theme I took away most immediately from this film.

There are two characters that I think are supposed to represent the audience, and neither are treated particularly well by the other characters. And by 'the audience', I'm going to be really self-centered and say that I mean the 30-somethings like myself who saw the original film when we were in that 8-12 year old bracket, or 'peak Jurassic Park' age, and who this film is clearly pandering to. Firstly, we have Gray Mitchell, a 10-ish year old who represents us when we first saw Jurassic Park: he's a dinosaur geek and is one of the only characters to show unrelenting enthusiasm for dinosaurs while visiting Jurassic World. Secondly, we have Lowery, the 30-something computer room dude, who wears an original Jurassic Park shirt and has dinosaur toys on his desk and is obviously super into the dinosaurs in the dinosaur theme park. He is us, now, grown up and nostalgic for the original film. Multiple times throughout the film, Gray's older brother tells him he needs to grow up, and points out that many of the things are for little kids. Claire makes fun of Lowery's shirt, and I think in general we're supposed to think he's kind of a weird man-child who hasn't really grown up.

There's a moment in the film where Gray and his brother Zach stumble upon the old Jurassic Park visitor center building. The T. rex cast skeleton lies on the ground covered in vegetation, and a little piece of the "When Dinosaurs Ruled the Earth" banner is visible. Zach uses it to make a torch so they can investigate the rest of the suspiciously-well-lit ruins. Visiting the old building felt like some gratuitous fan-service to me, but then burning the banner felt like a purposeful statement about rejecting the nostalgia of the original film.

Jurassic World is constantly setting up little nostalgic moments and then seemingly stomping all over them. It's like the filmmakers wanted to pay tribute to Jurassic Park but then were embarassed to show that they liked it – or maybe they didn't really like that movie at all, but wanted to make lots of money (success!). I don't know, but I find it thematically problematic and a bit sad, since the excitement over DINOSAURS! in the first movie is one of the defining aspects of that film, and that sense of wonder and grandeur has rarely been replicated. Jurassic World feels jaded, and like it's too cool for dinosaurs.


Can we talk about ladies in this movie for a moment?

Did we really need to introduce our main female character with the camera sweeping up her legs to her face? Was that absolutely necessary? Also, could we just not use the 'frigid, uptight workaholic woman needs to learn to loosen up and become sexually free with a man, and also needs to remember that all women will have children eventually' stereotype? COULD WE JUST NOT?

It's an intriguing throwback to the original Jurassic Park movie, which I feel successfully used the kids as a character development point for Alan Grant. But Sam Neill managed to portray Grant's discomfort with kids in a more organic way, and the movie gave that plotline a bit of breathing room to develop during some of its quieter moments AND its action sequences (see: sitting in the tree feeding Brachiosaurus; escaping the falling car in the tree; the fence). It's less believable with Claire Dearing, because she doesn't even spend any time with the kids in peril until almost the very end of the movie, at which point she basically worried herself into liking kids? Or something?

Look, not every movie is going to have (or should have) a Strong Female Character(TM), because there are lots of ways to be a lady just like there are lots of ways to be a dude. But the first two Jurassic Park movies had some cool female characters: Ellie Sattler, a palaeobotanist, who was brave and curious and smart! Lex Murphy, who knew those UNIX systems! Sarah Harding, who was a bit foolish but was also brave and curious! Kelly Curtis Malcolm, who gymnastic-ed a Velociraptor to death! In Jurassic World, we get a woman who has great power and authority (she runs a theme park full of dinosaurs!) being told she should be different at almost every opportunity, and we get a distracted babysitter who is killed in the most gratuitous, drawn-out sequence of all. Thanks, movie.


Ok, now let's actually talk about dinosaurs (and other prehistoric creatures) in Jurassic World.

Other palaeontologists have already beaten me to much of this, but I still had a few thoughts I wanted to share. Ultimately I don't have a big problem with the 'retro' dinosaurs of 1993 appearing in this film, because I'm willing to go with the flow in terms of continuity. But there were some pretty dumb things in this film:
· The pterosaur sequence was pretty godawful and brought the action to a screeching halt. I can't suspend disbelief that the pterosaurs would immediately rampage and murder a bunch of people, and I can't suspend disbelief over the physics of that sequence. Refrigerating that babysitter lady was also pretty awful. Sweet jeepers, Jurassic World, you're going to make me say something horrible: this sequence was better in Jurassic Park III. THERE. I hope you're happy.
·  I never really bought Indominus rex as anything more than a really big Allosaurus or Saurophaganax. (Sorry, theropod people! Allosaurus is cool, but not, like, THAT cool.) I did, however, like the incorporation of the camouflage idea from the Carnotaurus in the Lost World book, something that I had missed from the film adaptation. Overall, I'm frustrated that Indominus exists mostly so they had a dinosaur they could trademark. Because that's totally what that is, and everything else is secondary to that, including its incorporation into the plot.
· That mosasaur is just so gigantic. I'm on board, but that was starting to stretch credulity as well.
·  Why doesn't Rexy eat Blue after the fight? The mind boggles.

Ok, things I liked!
·  The Ankylosaurus gives Indominus the old what-for and doesn't immediately die like everything else! Indominus needs to really work at murdering that poor fellow. The design of the Ankylosaurus themselves is pretty terrible (wrong osteoderms, tail too curly, nostrils in the wrong spot, head generally a bit off), although I think it's meant to be consistent with Jurassic Park III.

Here's what Ankylosaurus REALLY looks like!

·  Dinosaur petting zoo! It should be for all ages!
· The big kaiju battle between Indominus and Tyrannosaurus was pretty well matched. I liked the little kick to JPIII when the Tyrannosaurus busts through the Spinosaurus skeleton on the way to the fight.
·  "Are they safe?""Oh no, under no circumstances, not even a little."


Some final Thoughts and Feelings

I haven't decided yet if I liked Jurassic World. I can't help but think back to the original Jurassic Park with its iconic visual moments and charming, if hokey, dialogue. While it was fun to see an operational Jurassic Park with rides and attractions, I don't feel like Jurassic World had much visual flair. It's really hard to beat dramatic, symbolic visuals like this:

Interesting camera angles like this:

Or quiet moments of terror like this:


And I miss the yellow and green and red colour palette of the original park, replaced here with chrome and blue and silver like every other washed out movie in theatres lately. It is also interesting that all of the big sweeping themes from the original soundtrack are used not for the dinosaurs, but for the manmade structures of the park itself. It really does feel like Jurassic World doesn't care about dinosaurs.
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Dinosaurs Unearthed!

June 25, 2015, 7:26 pm
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Growing up in Nova Scotia, despite its many excellent and significant palaeontological treasures, meant that there weren't many dinosaur fossils for me to gawp at regularly. The Nova Scotia Museum of Natural History (which I loved) had only a few small fossils on display, and besides an exciting appearance by the Dinosauroid when I was small, did not have any big traveling dinosaur exhibits come through. But when I was in Grade 1 or so, DINAMATION came to town and seared its robotic dinosaurs all over my brain forever. And so I think I will forever have a soft spot in my heart for animatronic dinosaur displays.

Mike Burns and I ran into some of the old Dinamation robots puffing away at the New Mexico Museum back in 2012!


Like Jurassic Forest and Dino Dino Dreampark, the traveling exhibit Dinosaurs Unearthed (at Telus World of Science in Edmonton for the summer) mostly features large animatronic dinosaurs, as well as some casts and interactive displays.

One of the main focuses of the exhibit is showcasing Chinese dinosaurs and fossils, and talking about recent research on the evolution of birds from dinosaurs. Probably one of the best parts of the exhibit is the large number of casts of feathered dinosaurs from China, including Sinosauropteryx, Caudipteryx, Microraptor, and Confuciusornis. These are still not particularly household names, so it's nice to see these on display, especially given the lack of feathers in Jurassic World's dinosaurs!



Just past the casts we have a diorama of Jehol Biota feathered dinosaurs, including (from left to right) the dromaeosaur Microraptor, the compsognathid Sinosauropteryx, the tyrannosaur Dilong, and the bird Confuciusornis. Some of the animatronics are better than others, and all are kind of weirdly oversized, but I think if there was a sign that said this was a diorama at 4x life size or something like that, that it would work pretty well.



My favourite cluster of dinosaurs was the set of Mongolian dinosaurs, including the first time I've ever seen Gigantoraptor anywhere! There's also a pretty dapper Alxasaurus in the front there.


I would have liked to see more cast fossils rather than sculpted reconstructions, and perhaps more fossils overall and a couple fewer animatronics. But generally the information presented in the exhibit was pretty good and had been recently updated, with references to the new research on Brontosaurus, and lots of recent behavioural, biomechanics, and ecology facts as well. Here's a nice display showcasing some of the cool imaging work done by the WitmerLab!



Until next time...watch out for that Shantungosaurus as you leave! 

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Woe betide those who summon the Galactic Coelacanth

June 29, 2015, 6:57 pm
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A couple of years ago I had an existential crisis when I realized that, in the time one of my papers had been in review (almost 8 months!), I could nearly have physically created an entirely new human being in my body, if I had so chosen. Thus began the saddest game in the universe that I like to play when I submit a paper: "What kind of animal could have been gestated in the time this paper has been in review?". And this became an even better running joke when one of my colleagues had a highly unusual review experience that lasted for several years, which completely exhausted the gestation times of real animals.

My amazing and lovely sister saw us talking about this on Facebook and went ahead and wrote an R script that tells you exactly what kind of animal you could have birthed while waiting for reviewer comments. And because I am always forgetting to save this amazing piece of code, I've gotten permission from Jessica to post it here for posterity. My sincere apologies to anyone who gets the Space Whale, and my deepest condolences to anyone who is graced by the presence of the Galactic Coelacanth. 

Click here for the R script!
Updated 30 June 2015: If you don't have R, you can also download a text file to see the code!
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Know Your Ankylosaurs: China Edition

July 24, 2015, 2:00 pm
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I'm in Utah digging up dinosaurs! But also, one of the last big chunks of my PhD thesis has just been published online at the Journal of Systematic Palaeontology. They are generously allowing free access to the paper through the end of August, so head on over and grab a copy while it's free! This time, I'm taking all of the knowledge gained from my previous taxonomic revisions, adding in some more taxa, and doing a revised phylogenetic analysis building on previous analyses to see how everyone shakes out and to learn a little bit more about ankylosaurid biogeography. I'll cover some of the taxonomic stuff over the next few posts, and finish off with the big picture of ankylosaurid evolution.


Pinacosaurus!

I've talked previously about the ankylosaurs of Mongolia, but I've also had the opportunity to study some of their friends from across the border in China. In particular, I got to see lots of specimens of Pinacosaurus, both from the Alag Teeg bonebed in Mongolia, and from Bayan Mandahu in China. Because Pinacosaurus specimens are relatively abundant and usually well preserved, there has already been lots of descriptive work on this taxon, including on the skull (and here, and here), hands and feet, and general postcrania. 

Baby Pinacosaurus are so teeny tiny! This one is from Bayan Mandahu and was collected during the Canada-China Dinosaur Project back in the 1980s.

I've discussed just a few new points about Pinacosaurus, especially about how we tell the two species of Pinacosaurus apart. Pinacosaurus grangeri is known from lots of specimens, almost all of which are juveniles; it has relatively short horns at the back of its skull, a constriction in the snout between its nose and its eyes, and a notch in the rough ornamentation above each nostril. Pinacosaurus mephistocephalus is known from just one specimen (also a juvenile), and it has long squamosal horns, no constriction in its snout, and no notch in the ornamentation above each nostril (it looks like it does on one side, but I think this is just damage given that it is not present on the other side). Both species are known from Bayan Mandahu, and so it is reasonable to ask whether or not these could represent the same taxon – given the differences in skull morphology, I suspect we're not looking at intraspecific variation here, although more specimens of P. mephistocephalus would be very helpful in this regard!


Crichtonsaurus becomes Crichtonpelta

Crichtonsaurus is another cool ankylosaur that has received surprisingly little attention given its Jurassic Park affinities. Two species have been named: Crichtonsaurus bohlini (the type species), and Crichtonsaurusbenxiensis. Crichtonsaurus bohlini is, unfortunately, a very incomplete jaw that does not bear any diagnostic features, and so we argue that Crichtonsaurusshould be considered a nomen dubium. Crichtonsaurus benxiensis, on the other hand, is a great specimen with a really good skull and a fair bit of the postcrania, and the skull has some unique features that make it easy to distinguish from other taxa, most specifically the upturned quadratojugal horns. We've proposed the new name Crichtonpelta benxiensis for this material – Crichtonsaurus was a good name and we wanted to keep the replacement name similar, so now we have Crichton's shield instead of Crichton's lizard.



During the Flugsaurier symposium in 2010, while I was visiting Beijing and the IVPP, we took a field trip out to Liaoning and visited the Sihetun Fossil Site. It has a cool museum, including a mounted Crichtonpelta skeleton! I don't think this specimen has been described, but it does corroborate certain aspects of the holotype skull. Crichtonpelta seems to lack discrete caputegulae (tile-like ornamentation) on its skull, which gives it a similar appearance to Pinacosaurus. I don't think the osteoderms have been placed quite correctly on this skeletal mount – I think they've been tipped on their sides so that the keel forms part of the 'base', giving it a somewhat stegosaur-like appearance.


Liaoningosaurus and Chuanqilong

I'm going to talk more about Liaoningosaurus in a few months, but it is one cool little ankylosaur! At only about 30 cm long, the holotype is one of the smallest known ankylosaur specimens and probably represents a very young individual. There may be a few osteoderms in the cervical/scapular region, but that's about it. I've previously argued that the putative plastron in this specimen is more likely skin impressions, which is still pretty cool because we don't have a lot of belly skin for ankylosaurs. 

Liaoningosaurus! YAY!

I also wanted to give a shout out to here to Chuanqilong, a larger ankylosaur from Liaoning that was described last summer and which didn't make it into my thesis but which I did include in the revised phylogenetic analysis in the final paper.

Here's Chuanqilong, from Han et al. (2014).


Dongyangopelta, Taohelong, and Sauroplites

Let's finish off this post today with a triad of interesting but enigmatic ankylosaurs. Dongyangopelta and Taohelong are relatively new entries to the world of ankylosaurs, with both taxa appearing in 2013. Neither are particularly complete, but they are interesting because both species possess chunks of fused osteoderms, which would have been found over the pelvis and which are most commonly encountered in nodosaurids and 'polacanthids/polacanthines', and are presently unknown in ankylosaurids – and indeed, Yang et al. described Taohelong as the first example of a polacanthine from Asia. Nodosaurids (including 'polacanthines' as basal taxa within this clade) have been tentatively identified from Asia previously (an interesting but fragmentary specimen from Japan may be a nodosaurid), but to find a Polacanthus-like animal in Asia is unexpected and very interesting. The two species can be differentiated based on the morphology of these pelvic shield pieces. Dongyangopelta comes from the Chaochuan Formation, and another ankylosaur, Zhejiangosaurus, had been named from that formation in 2007; it may eventually shake out that Dongyangopelta is a junior synonym of Zhejiangosaurus, but in the absence of overlapping diagnostic material we opted to keep these taxa separate for now.

Pelvic shield fragments - Dongyangopelta redrawn from Chen et al. (2013), Taohelong redrawn from Yang et al. (2013), and Sauroplites redrawn from Bohlin (1953).

Sauroplites, on the other hand, is a very old name that has been largely overlooked in recent assessments of ankylosaurs. The material was originally described by Bohlin in 1953, but sadly the whereabouts of the original material is unknown today (although there are casts at the American Museum of Natural History). I think Sauroplites was overlooked for a while because it's based off of osteoderms alone, and it's hard to assess diagnostic characters in osteoderms sometimes because they vary so much along the body. This is partly why I like cervical half rings and pelvic shields – in these structures, you can understand the positions of the osteoderms on the body and directly compare patterns and morphologies across different taxa. Supposedly, the osteoderms for Sauroplites were preserved in their original positions when the specimen was excavated, and if so, it's a bit surprising that more of the skeleton was not preserved. Bohlin correctly identified some of these pieces as elements of the sacral armour, and the morphology of these pieces can be used to differentiate Sauroplites from Taohelong and Dongyangopelta, and we consider Sauroplites to be a valid, but poorly known, taxon. It's good to revisit poorly figured and fragmentary taxa from time to time, because new discoveries might help put those pieces in context.


Next time: we head south! See you then!
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Know Your Ankylosaurs: Gondwana Edition

July 31, 2015, 7:59 pm
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Last time, I talked about the ankylosaurids of China, and today we're talking about Gondwanan ankylosaurs. Gondwana basically refers to the continents of today's southern hemisphere; when the supercontinent Pangaea broke apart, it split into two large continents – Laurasia in the north, and Gondwana in the south. Gondwana includes South America, Africa, Australia, and Antarctica, and, somewhat nonintuitively, India (India kind of beelined into Asia from Australia and that's why we have the Himalayas). Almost all of the ankylosaurs we know about are from the Laurasian continents, which means that the few found in Gondwana are phylogenetically and biogeographically interesting: do they represent southern branches of the ankylosaur family tree, or new migrations into Gondwana from Laurasia? Let's take a closer look:

Minmi paravertebra and Minmi sp.
Minmi is the iconic Australian ankylosaur. Most people, when they think of such things, think of the spectacular referred skeleton with agood skull and in situ armour.

The Smithsonian has a cast of the specimen - here's a section of the ribcage, showing some of the osteoderms in their original arrangement.


Sadly, the holotype is extremely fragmentary and has few elements to make a diagnosis with. Originally, one of the most striking features of Minmi paravertebra was the presence of paravertebral elements, thin rod-shaped bones along the dorsal vertebrae. These were originally interpreted as ossified tendons of the dorsal muscles, and although these are cool to see in Minmi, they are not really unique to Minmi or even to ankylosaurs, since ossified tendons are ubiquitous throughout Ornithischia. One unusual aspect of these ossified tendons is that one set has a flattened, expanded front end. These were interpreted as possible ossified aponeuroses (aponeuroses are sheets of connective tissue in between muscles and tendons). This particular aspect of the ossified tendons IS very unusual, because ossified aponeuroses are extremely rare in animals. While I was hunting around for information about ossified aponeuroses, I came across a very odd case study about mouse deer (Tragulus)– the males completely ossify the aponeuroses above their pelvis and back, creating a carapace-like structure! This is super weird and I would love to investigate this further at some point.

WHAT THE WHAT.

Ossified aponeuroses have since been identified in the European nodosaur Hungarosaurus, which poses a bit of a problem for Minmi: since this feature was one of the only diagnostic characters for Minmi, and since it is now found in an animal that is very unlikely to be Minmi given the spatial and temporal distance between the two, Minmi paravertebra is left without diagnostic characters. A sticky situation that will hopefully be resolved in the future by people who have spent time with the original fossil material!

Antarctopelta
Did you know that the first dinosaur discovered in Antarctica was an ankylosaur? Cryolophosaurus might get all the buzz, but Antarctopelta was first to the press. Antarctopelta is a very interesting little ankylosaur, which I had the chance to study during my visit to Argentina back in 2011. The material is fragmentary but tantalizing, with some pieces of the pelvic armour that are reminiscent of ankylosaurs like Stegopelta and Glyptodontopelta from North America. Unfortunately, in the course of my research I noticed that some of the bones attributed to Antarctopelta and used to help diagnose the taxon didn't quite seem like they came from an ankylosaur. The material was found on an ancient beach strandline with some marine fossils mixed in, and it looks like some of the material originally interpreted as ankylosaurian might be better interpreted as belonging to a mosasaur and a plesiosaur. In the end, we weren't left with any diagnostic characters for Antarctopelta and we should consider that a nomen dubium for now, but there's definitely an Antarctic ankylosaur and I hope at some point some better material is recovered so we can determine the best name for this guy.

The Argentinian ankylosaur
Finally, I also had the chance to study the only described ankylosaur from Argentina. This is also a fairly fragmentary specimen, and it came from a channel lag deposit so it's possible that more than one individual is represented. There are osteoderms, some vertebrae, and a femur, and all are very small – about the same size as the juvenile Anodontosaurus (originally described by Coombs as Euoplocephalus) from Alberta. The femur is interesting because it has some very prominent ridges running lengthwise on it, which seem to be intermuscular lines; these are present but very faint on some other ankylosaurs, and I haven't encountered anything like that in other ankylosaurs. There also may be fragments of the cervical half rings preserved as part of this specimen, since there are some unusual curved osteoderms with multiple peaks and keels. These don't bear any resemblance to other half rings I've looked at, and cervical half ring morphology seems to be taxonomically informative for ankylosaurs. Together, the weird intermuscular lines and unusual cervical half ring fragments might be enough to diagnose the Argentinian specimen as a new taxon, although we withheld from doing so at present.


Here's the specimen on display at the Museo Carlos Ameghino in Cipoletti!

There have been reports of some possible ankylosaur material from India and Madagascar, although much of this material is either very fragmentary (a single tooth from Madagascar), or has not been described (material from India). Stay tuned to find out more about how these rare ankylosaurs fit into the big picture of ankylosaur evolution!


Next up: a grab bag of everybody else!
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Know Your Ankylosaurs: North American Odds and Ends Edition

August 7, 2015, 12:47 pm
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I've covered many of the North American ankylosaurs in my previous papers and blog posts. In 2013, I argued that what we thought was Euoplocephalus was more likely 4 taxa– Anodontosaurus, Dyoplosaurus, Scolosaurus, and Euoplocephalus proper. Then in 2014 we described a newankylosaurid, Ziapelta, from New Mexico. There are a few other taxa that had previously been proposed to be ankylosaurids, so let's take a look at them here.

Aletopelta, Stegopelta and Glyptodontopelta
Aletopelta is one of the more tantalizingly enigmatic ankylosaurs from North America. It's from a weird place – California – which may have been much further south 75 million years ago compared to its current position. It was also found in marine sediments, and the decaying carcass had formed a little reef, with oysters encrusting the ribs. The only known specimen of Aletopelta is relatively complete, all things considered, with the osteoderms in situ over part of the pelvis, the legs partially articulated, and with various odds and ends like osteoderms and vertebrae. Unfortunately, the ends of the bones are often chewed apart, and some of the material is a bit hard to interpret.

Here's the articulated pelvis and hindlimbs, and some other armour pieces, on display at the San Diego Museum of Natural History.

Regardless, Aletopelta is a very interesting ankylosaur. It has an unusual osteoderm morphology over the pelvis, with small hexagonal osteoderms closely appressed to each other. Ankylosaur pelvic armour seems to come in two major flavours: fused rosettes, like we saw in Dongyangopelta and Taohelong (and perhaps most famously in Polacanthus), and interlocking hexagons, like in Stegopelta, Glyptodontopelta, and Aletopelta. Tracy Ford suggested that ankylosaurs with these hexagonal pelvic shields might represent a clade (dubbed Stegopeltinae) of ankylosaurids. Glyptodontopelta has since typically been interpreted as a nodosaurid, as has Stegopelta, but the most recent interpretation of Aletopelta was that it was an ankylosaurid. In the revised phylogeny in my new paper, we found Stegopelta and Glyptodontopelta as nodosaurids, but Aletopelta as a very basal ankylosaurid. However, although Ford and Kirkland reconstructed Aletopelta with the typical ankylosaurid tail club, I don't think that it possessed one: the preserved distal caudal vertebrae don't show any of the lengthening or other modifications that are characteristic of ankylosaurid handle vertebrae.

An updated restoration of the known elements in Aletopelta - the main differences between this and Ford and Kirkland's reconstruction are the absence of a tail club, and uncertainty over what the head should look like.


Cedarpelta

Cedarpelta is an important taxon for understanding the biogeography and evolution of ankylosaurids, and I wish we had more specimens! I don't have many new comments to add about this taxon, since Ken Carpenter published a great description of the disarticulated skull back in 2001. Cedarpelta has been interpreted as a shamosaurine ankylosaur, as a relative of taxa like Gobisaurus and Shamosaurus (which I'll talk about in the next post) from Asia, and thus may point towards a mid Cretaceous faunal interchange between these two continents. In our revised phylogenetic analysis, we didn't find Cedarpelta as the sister taxon to either Gobisaurus or Shamosaurus, but it does come out as a basal ankylosaurid in their general neighbourhood, and I honestly wouldn't be surprised if future analyses or new taxa show support for it as a shamosaurine ankylosaur after all.

Nodocephalosaurus

Nodocephalosaurus! What a fun ankylosaur. It's really quite unlike the other ankylosaurids from North America, which typically have flat, hexagonal cranial ornamentation. Instead, Nodocephalosaurus has bulbous, conical cranial ornamentation. Bulbous cranial ornamentation is typical of Campanian-Maastrichtian Mongolian ankylosaurs like Saichania and Tarchia, but in those taxa the ornamentation is pyramidal rather than conical. The front end of the snout in Nodocephalosaurus is also unusual, because there's no obvious narial opening and instead the ornamentation has a stepped appearance. Hopefully better specimens with more complete snouts will resolve this weird morphology. I've also reinterpreted the position of the quadratojugal horn compared to Sullivan's original figures – the horn should be rotated forward so that the bottom margin of the orbit is complete.

Nodocephalosaurus holotype skull in dorsal and left lateral views.


Tatankacephalus

I don't have much to say about Tatankacephalus because I didn't look at the original material myself, but the previous phylogenetic analysis by Thompson et al. recovered it as a nodosaurid rather than an ankylosaurid as originally suggested by Parsons and Parsons, and we found the same result. Overall, Tatankacephalus is VERY similar to Sauropelta, so this is perhaps not surprising.


Up next: More odds and ends, but after I return from Utah!
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Know Your Ankylosaurs: Mongolian Odds and Ends Edition

August 19, 2015, 6:03 pm
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I'm back in civilization, so let's get back to ankylosaurs! Ready Set Go!


Gobisaurus, Zhongyuansaurus, and Shamosaurus

Shamosaurus is a really interesting ankylosaurid from the Zuunbayan Formation of Mongolia. Unlike later ankylosaurids, it still has a relatively long snout like you see in basal ankylosaurs and nodosaurids, and it lacks the distinctive tile-like skull ornamentation of ankylosaurs like Euoplocephalus or Saichania, instead just having a granular, pebbly texture on the skull surface. Gobisaurus, from the Ulansuhai Formation of China, is nearly identical in appearance, and only a few features distinguish these two taxa, namely the length of the tooth row relative to skull length and the orientation of the pterygoids. (Indeed, I think you could make an argument for subsuming Gobisaurus into Shamosaurus as Shamosaurus domoculus, but I'm generally reluctant to start making new combinations given that generic separation is pretty arbitrary anyway.)

Shamosaurus and its too-cool-for-school cervical half rings, on display in Moscow.

Gobisaurus and Shamosaurus are sister taxa; the name Shamosaurinae was proposed at one point and there's no reason to discard it at present even though it only contains two taxa. Shamosaurinae is the sister taxon to Ankylosaurinae. I also identified one new character that links Gobisaurus and Shamosaurus together which isn't present in other ankylosaurids: both taxa have a distinctive groove on each premaxilla, the purpose of which is unknown but there you go. There have been some suggestions that Cedarpelta (from North America) is also a shamosaurine ankylosaurid, and while I find the overall morphology of Cedarpelta to be pretty compelling for placing it in a clade with Gobisaurus and Shamosaurus, I didn't recover it with those taxa in my analysis (it came out more basally-positioned). However, I wouldn't be surprised if Cedarpelta winds up in Shamosaurinae at some point in the future as we find more specimens of both it and Gobisaurus and Shamosaurus.

Zhongyuansaurus was originally described as a nodosaurid ankylosaur partly because of its long snout, but it's indistinguishable from Gobisaurus (except for being smashed and flattened). The holotype is also a subadult (or at least not fully skeletally mature), since some of the cranial sutures are still visible towards the back of the skull. There are some interesting things going on with the postcrania of Zhongyuansaurus, but that's a story for a few weeks from now so STAY TUNED NO SPOILERS IF YOU'VE READ MY THESIS.


Tsagantegia

Of all of the more obscure ankylosaurs I looked at during my PhD, Tsagantegia might be my favourite for being the most surprising in person compared to what I had read about it. Tumanova included a line drawing of the specimen in her original description, which has been oft reproduced, but interestingly it doesn't really do justice to the original specimen (despite being a pretty nice drawing). The line drawing shows a long-snouted ankylosaur with amorphous cranial ornamentation, not dissimilar to Shamosaurus, but with a wider premaxillary beak more typical of later ankylosaurs. In person, however, the skull has distinct cranial caputegulae like we see in Euoplocephalus and Ankylosaurus! It's a pretty cool ankylosaur and I think it's probably really important to understanding the dispersal of ankylosaurs from Asia into North America and the diversification of ankylosaurids in the Campanian-Maastrichtian of Asia, but it's really hard to pin down the age of the Bayan Shiree Formation, and we don't have any postcrania for this taxon. I'm sure I'll be revisiting this guy in the future.

Heck yeah Tsagantegia!

Here it is again but in a more different view!

Talarurus

Way back when I originally started this blog in 2010, I had travelled to Korea to spend some time working in the Hwaseong paleo lab preparing Talarurus material and generally studying the ankylosaur material they had collected from the Gobi. Talarurus, like Tsagantegia, is also from the Bayan Shiree Formation but is clearly distinct. The holotype skull has very subtle cranial ornamentation that takes the form of small cones, rather than flat hexagonal tiles like Euoplocephalus, or bulbous pyramids like Saichania. Weirdly, this configuration is also present in the North American taxon Nodocephalosaurus – either this ornamentation style has convergently evolved, or, as I recovered in my analysis, these two taxa are closely related despite being fairly widely separated geographically and temporally. This is another ankylosaur that I'm sure we'll talk about again.
Talarurus butt in Moscow. The skeleton on display is a composite of several individuals from the same locality, and the skull is totally sculpted and a bit out of date.

Here's the holotype skull, with its weird, weird ornamentation.


Saichania

I've talked about Saichania fairly extensively here last year, but there were a few new things added in this most recent paper: Tianzhenosaurus and Shanxia (both from China) are, most likely, junior synonyms of Saichania, making this the most geographically widespread of the Asian ankylosaurids. Tianzhenosaurus has a nearly identical cranial ornamentation pattern when compared to Saichania, and I couldn't identify any differences that were outside of the usual ornamentation pattern variation we see in something like Euoplocephalus. Shanxia is known from the same formation but from a less well preserved skull, but the morphology of the squamosal horn is consistent with that of both Tianzhenosaurus and Saichania and therefore it probably represents the same taxon.



Next up: what's the big picture here, anyway?
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Know Your Ankylosaurs: Everybody's in this Together Edition

August 23, 2015, 3:33 pm
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So with all of those posts about ankylosaur taxonomy over the last few weeks, what have we learned about the evolution of this group? Over the course of my PhD research, I was able to identify a bunch of new characters that seemed useful for understanding ankylosaur phylogenetic relationships, including characters related to the cranial ornamentation, pelvis, and osteoderms. Although ornamentation and osteoderms can be tricky, they can still yield useful information if you're careful about how you construct the characters.

Here's a sampling of some of the new characters from the supplementary file that goes along with the paper. Long live rainbow ankylosaur skulls.


With all the new information, here's what the results of the analyses gave us (click to embiggen):



From this, we can take away some interesting points:

1. Gondwanan ankylosaurs are probably not ankylosaurids, but they also don't form a single evolutionary group. Whatever "Minmi" is, it's a very basal kind of ankylosaur, possibly outside the split between Ankylosauridae and Nodosauridae. It's a little bit harder to say what's going on with "Antarctopelta" (previously considered an ankylosaurid), and the Argentinian ankylosaur: both came out as relatively derived nodosaurids, but my dataset isn't designed to test the interrelationships of nodosaurids. I wouldn't be surprised if future analyses incorporating more nodosaurids and more nodosaurid-based characters found that these two species were closely related. It would also be interesting to know which lineage of nodosaurids (probably a lineage from North America) dispersed into South America in the Late Cretaceous in order to give us these two ankylosaurs.

2. There are nodosaurids in the early-mid Cretaceous of Asia, but not necessarily the ones that have been proposed previously. Zhongyuansaurus, for example, was first described as a nodosaurid but is instead a junior synonym of the shamosaurine ankylosaurid Gobisaurus. However, a couple of taxa, like Taohelong, Sauroplites, and Dongyangopelta, are recovered as basal nodosaurids. At present, there doesn't seem to be much overlap between Asian nodosaurids and ankylosaurids, which is interesting! Why didn't nodosaurids hang on in Asia once ankylosaurids evolved, when the two groups seem to have coexisted pretty happily in North America later on?

3. The ankylosaurids from the Late Cretaceous of North America represent a dispersal of Asian ankylosaurines sometime during the early-mid Late Cretaceous. The earliest ankylosaurine is probably Crichtonpelta, from China, and North American ankylosaurines are a deeply nested clade within Ankylosaurinae. We propose the new name Ankylosaurini for the North American ankylosaurines (plus Talarurus, for now).

Here, have some frowny-faced rainbow ankylosaurs. Ankylosaurs are very serious dinosaurs.

4. Where do ankylosaurids first evolve? Unfortunately, that question isn't easy to answer right now: down at the base of Ankylosauridae, there's a mix of taxa from North America and Asia. The position of Gastonia as an ankylosaurid tips the scales slightly in favour of a North American origin for the clade, but some analyses recover this taxon as a nodosaurid, so I think we should be a little cautious about this result. One step up the tree, we've got a polytomy of Aletopelta and Cedarpelta (both from North America) and Liaoningosaurus and Chuanqilong (both from China). Does Ankylosauridae originate in North America with something like Cedarpelta, with a subsequent migration and diversification into Asia? Or does this group originate in Asia with something like Liaoningosaurus and Chuanqilong, and Cedarpelta represents an immigration into North America?

5. And finally, what's going on with ankylosaurids in the mid-Cretaceous of North America? Why don't we find any ankylosaurids between Cedarpelta and the later ankylosaurins? Did 'endemic' North American ankylosaurids go extinct during that time? And why does Aletopelta have such a weird basal phylogenetic position despite being from the Campanian? I don't really have answers for some of these questions, although if you come to the Society of Vertebrate Paleontology meeting in Dallas this October I'm going to try addressing some of them. For now, Aletopelta remains the biggest ankylosaurid enigma to me – it really shares very few things in common with the other Campanian ankylosaurids and I doubt it is an ankylosaurin from the Asian immigration into North America – could it represent a distinctive lineage of North American ankylosaurids stemming from things like Gastonia or Cedarpelta, for which we just don't have other representatives at the moment? Or, is it a nodosaurid masquerading as an ankylosaurid because I haven't sampled the right taxa or characters?

Darn you Aletopelta, why must you vex me so?

As usual, I wind up with more questions than answers every time I try to figure something out.

That wraps up the summaries for this paper, but stay tuned for some more cool research coming out in the next few weeks, and some summer fieldwork recaps!



Arbour VM, Currie PJ. In press. Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology.
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How the ankylosaur got its tail club

August 31, 2015, 8:23 am
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Ankylosaur tail clubs are odd structures, odder than they are usually given credit for. They represent substantial modifications to two different skeletal systems – the endoskeleton, in the form of the caudal vertebrae, and the dermal skeleton, in the form of the caudal osteoderms. The centra of the caudal vertebrae lengthen but stay robust, and the neural arches undergo huge changes, such that the prezygapophyses, postzygapophyses, and neural spine become a robust, V-shaped structure on the top of the centrum, and which creates a tightly interlocking vertebral series with almost no flexibility. We call this the handle of the tail club. The osteoderms at the tip of the tail smush together and two of them become huge: although the tail club knob is small in some species, there are colossal knobs exceeding 60 cm in width. The ankylosaur tail club represents one of the most extreme modifications to the tail in terrestrial tetrapods.

Look at that thing. That is a weird thing.
(This is UALVP 47273, a really nice club that I studied for my MSc work on tail club biomechanics.)

One of the questions I became interested in during my MSc research on ankylosaur tail club biomechanics was how the tail club evolved in the first place. Most ankylosaurs with tail clubs are known from a relatively narrow slice of time right at the end of the Cretaceous, but when and where did the tail club first evolve? Did the stiffening of the tail occur before the enlargement of the tail osteoderms, or vice versa? Or did both changes happen at about the same time? This was a fun question to address during my PhD research, once I had a fairly well resolved phylogeny of ankylosaurids, and once I had looked at tons of ankylosaurid fossils.

So, how did the ankylosaur get its tail club? Well, based on what we see in the fossil record, it looks like the changes to the vertebrae predate the changes to the osteoderms – in other words, the handle comes first and the knob comes later. There is at least one ankylosaur out there that seems to have a tail club handle but not a knob: Gobisaurus!


Hello Gobisaurus! Many many thanks to my friend and colleague Sydney Mohr for preparing this awesome illustration of Gobisaurus for me.

Gobisaurus, a shamosaurine ankylosaurid, has a really nice complete tail club handle that is indistinguishable from other ankylosaurid tail club handles, but does not have a knob. And it's not just because the knob is broken off – it seems as though the last vertebrae in the tail are preserved, because they look very similar to the terminal vertebrae in a CT scan of a tail club from the University of Alberta collections. It's likely that Gobisaurus had osteoderms along the sides of the tail like we see in most other ankylosaurs, but it doesn't appear that there were osteoderms tightly enveloping the tip of the tail.

An even earlier ankylosaur seems to show some changes towards acquiring a tail club handle, as well. Liaoningosaurus, a basal ankylosaurid known only from a very small juvenile, has distal caudal vertebrae where the prezyapophyses extend about 50% the length of the adjacent vertebra. This is what we see in ankylosaurid tail clubs, but not in more basal taxa like Mymoorapelta where the prezygapophyses are much shorter. Liaoningosaurus is missing the tip of the tail and also lacks osteoderms on most of its body because it's a juvenile, so it's harder to say whether or not it had a tail club knob based just on the fossil alone.


I also did a cool and relatively simple thing with my phylogenetic tree to see if I could better understand the likelihood that some ankylosaurs without preserved tail material had a tail club handle or full tail club with a knob. Unsurprisingly, all shamosaurine and ankylosaurine ankylosaurids probably had a tail club handle. Liaoningosaurus is part of a basal polytomy of ankylosaurids, and it was a bit more equivocal whether or not any of these taxa was likely to have a tail club handle or not, partly because another basal ankylosaurid in this region of the tree, Chuanqilong, does not have modified distal caudal vertebrae.

All ankylosaurine ankylosaurids more derived than Pinacosaurus (so including things like Tsagantegia, Saichania, Euoplocephalus, etc.) almost certainly had a tail club knob, and shamosaurine ankylosaurids probably did not. Crichtonpelta, the most basal ankylosaurine, may or may not have had a tail club – we'll need more data to know for sure. There is amounted skeleton of Crichtonpelta at the Sihetun visitor center in Liaoning, and it is shown with a tail club, but it isn't clear whether or not this is sculpted or original material belonging to this specimen, and a full description of this material is necessary.


Gobisaurus and Liaoningosaurus both lived much earlier than the more familiar tail-clubbed ankylosaurs: Gobisaurus is no younger than 92 million years old, and Liaoningosaurus is about 122 million years old. The earliest ankylosaurid with a tail club in the fossil record is Pinacosaurus(from the Campanian), although there is a caveat to this: Talarurus, which is a bit older than Pinacosaurus, should have a full tail club based on its position in the phylogenetic tree, and while a tail club handle is known for this taxon, we haven't found a tail club knob for Talarurus. Talarurus is in kind of a weird spot phylogenetically, since it's from Mongolia but comes out as closely related to North American ankylosaurines, so I think it's worth keeping an eye on this taxon in the future – perhaps Talarurus is another taxon with only a handle and not a knob, which would fit a bit better with its chronologic position if not its phylogenetic position.


Regardless, the changes to the vertebrae of ankylosaurs, starting with Liaoningosaurus at least 122 million years ago and continuing on towards Gobisaurus about 92 million years ago, seem to have occurred long before ankylosaurs evolved a huge osteodermal knob at the end of the tail. Was a stiff tail as good a weapon as a full tail club with a knob? What drove the evolution of the knob so long after the evolution of a stiff handle? And why did ankylosaurs even evolve a tail club at all? Now that I've had fun investigating how ankylosaurs might have used their tails, and how the tail club evolved, the next question feels like it should be 'why'....so stay tuned for more tail club fun over the next year or so as I make an attempt at that question!


Read it for yourself! Arbour VM, Currie PJ. In press. Ankylosaurid dinosaur tail clubs evolved through stepwise acquisition of key features. Journal of Anatomy.
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Snapshots from the Field Museum

September 12, 2015, 6:15 pm
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Last week I got a chance to visit the Field Museum in Chicago for the first time! It's a great big museum with lots of cool stuff, so I figured I'd share a few impressions from my lunchtime jaunts through the exhibits. Let's get started with all the fossil exhibits outside of the main fossil hall (there are several, but some of them are kind of hidden away!).

SUE

Sue the Tyrannosaurusis most definitely not hidden away, and occupies a place of pride in the museum's main entrance hall. Sue is undeniably a great fossil, although I (and I suspect probably some other palaeontologists as well) have mixed feelings about this fossil: it's incredibly well preserved, but the intense backstory to Sue's acquisition is filled with several unpleasant twists and turns. I'm glad Sue found a home in a museum, but I wish it hadn't been placed up for auction - Sue's auctioning may not have directly led to the trend of putting dinosaurs up for auction for millions of dollars, but I feel like it set a bad precedent all the same.

One thing that's particularly enjoyable about this specific Tyrannosaurus skeleton are the abundant pathologies to be found. Sue has a busted/infected shin, holes in its jaw, and rough bumpy spots on its vertebrae. These vertebrae near the end of the tail have a big mass of crinkly bone around them. It's obvious Sue got up to some trouble during its life, and it's interesting to speculate on the causes of the various oddities in the skeleton (and indeed, others have!).


 Extinct Madagascar

Sadly, this exhibit is tucked so far out of the way that basically nobody had wandered back there besides me (you need to go through the conservation gallery to reach it). It's also a little bit specimen-sparse, a trend I've noticed recently in many museums and which I find somewhat concerning. However, I feel like it makes up for the lack of 3D objects in its cool and unusual subject matter - the extinct fauna of Madagascar. The main point to the gallery was showcasing the social media response to new images of Madagascar's prehistory, and the scientific process that went into those images. It was an interesting way to approach the topic, but might have been more compelling with video, audio, or more fossils.

It was pretty cool to see an Aepyornis (elephant bird) egg and life-size silhouette. They really were terrifyingly large and strange birds.

A highlight for me was this Palaeopropithecus skeleton - a lemur that lived and looked like a sloth.


Tracking the Reptiles of Pangea

Tucked away in the African mammals area was a room devoted to palaeontological fieldwork in Tanzania, featuring the newly described silesaurid Asilisaurus! This isn't a skeleton you're going to see in most museums - I only wish more people had been stepping into this little exhibit room to check it out.

A nice touch was showing the original fossil material in its cabinet-ready storage foam. Those are some nice fossils.


And one last fossil....

Seriously, how were these machines not in constant use? They're in the hallway leading towards the bottom-floor cafeteria, and you can get yourself a freshly-made retro Triceratops, Brontosaurus, Tyrannosaurus, or Stegosaurus. I made a Brontosaurus and consider it $2 extremely well spent, especially since it meant I got rid of a bunch of dimes and nickels I didn't know what to do with:



Next time: Evolving Planet!
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