Thoughts on Tarbosaurus, Part 2

In my last post I talked about the role of museums in conserving fossil resources, with regards to the recent news about the Tarbosaurus auction. I wanted to address some of the other frequent comments I have seen on blogs and news articles. So, we’re now on to:

Comment 2: How do we know the tyrannosaur came from Mongolia? (and the related question, which I’ve decided to lump with this one: Why does the auction company, and subsequent news stories, refer to the specimen as Tyrannosaurus bataar while palaeontologists call it Tarbosaurus?

The first thing we need to address with these questions is the concept of ‘species’. In high school, most of us will have learned that a species is defined as a group of interbreeding individuals that can produce fertile offspring. This is called the Biological Species Concept. What many people may not know is that this is just one of many species concepts. Palaeontologists can’t go back in time to check on which dinosaurs were interbreeding, so the biological species concept can’t really be used in palaeontology. Instead, we generally use the Morphological Species Concept, which essentially boils down to ‘a species is a group of individuals that look like each other and not like others’.

Much of the arguing and debate in palaeontology results from the problems associated with the morphological species concept, and that is because individuals from the same species can look different from each other, and individuals from different species can look similar to each other. Biologists working on still living (‘extant’) animals need to worry about three main sources of morphological variation:

1.      Changes that occur during growth: An older individual of the same species can look different from a younger one.

2.      Sexual dimorphism: Males and females of the same species may look different.

3.      Normal individual variation: Individuals within a species can look different from each other because of normal variation resulting from small genetic differences and environmental differences. As an example, think about all the different dog breeds there are today. All dogs can interbreed (theoretically, although surely a Great Dane crossed with a Chihuahua must be pushing the limits of what is practical...) and produce fertile offspring, and belong to the same species, Canis familiaris. On top of that, all dogs are descended from domesticated grey wolves, and so many scientists regard them as a subset of the species Canis lupus. In taxonomic terms, this is called a subspecies, and we would write it as Canis lupus familiaris.

 Via Wikimedia Commons.

Palaeontologists need to add one more source of variation because we work with fossils, and that is:

4.     Changes that occur during fossilization (‘taphonomy’): Most fossils preserve only the skeleton, and so information from soft tissues like colour, integument, and muscles is lost. Skeletons become disarticulated, and individual bones get broken. All of this reduces the amount of information we have to work with. Finally, the remaining bones can become squished and distorted because of the extreme forces that occur as rocks form.

 Disarticulated Argali sheep skeleton in Mongolia, 2010.

Finally, it is important to remember that the natural world doesn’t always fit into discrete categories, and that the concept of species, genus, etc. is something that humans have created to help sort living things into workable categories. How many differences do two populations need to have in order to call them different species? How many differences until we split things into different genera? There isn’t really an answer to those questions, and so deciding on what are ‘species-level’ differences vs. ‘genus-level’ differences is the source of much debate.

But that’s ok, because that is a big part of what is fun about taxonomy and palaeontology!

So, moving on to Tyrannosaurus rex vs. Tyrannosaurus bataar vs. Tarbosaurus bataar. Tarbosaurus bataar and Tyrannosaurus rex have several morphological differences in the skull, but these are not necessarily obvious if you’re not accustomed to anatomical terminology or used to looking at skulls. Nevertheless, they are present, and there is an excellent, free to access paper in Acta Palaeontologica Polonica that you can go download right now to see for yourself. In a nutshell, the skull of Tarbosaurus is narrower than Tyrannosaurus when you look at it front on, and the nasal bones (the bones along the top of the snout) are domed near the front of the eyes. Additionally, the arms of Tarbosaurus are proportionately even shorter relative to the rest of the body than those of Tyrannosaurus, which are already pretty short.

Tarbosaurus bataar partial skull at the Palaeontological Institute in Moscow.

Tyrannosaurus rex skull at the Royal Tyrrell Museum in Drumheller, Alberta.

It’s pretty clear that Tarbosaurus bataar and Tyrannosaurus rex represent different species, because these differences are geographically separated. Small-armed, narrow-skull tyrannosaurs are only found in Mongolia, and longer-armed, wider-skull tyrannosaurs are found only in North America. You could make an argument that perhaps the differences are insufficient to warrant having two genera, in which case the genus Tyrannosaurus has priority over Tarbosaurus because it was named first. However, most palaeontologists accept both the genus Tarbosaurus and the genus Tyrannosaurus as being valid. So why did the auction house consistently call their skeleton Tyrannosaurus bataar? I can’t say for sure, but I suspect it is because Tyrannosaurus is much more a household name than Tarbosaurus, and this makes the skeleton more recognizable and interesting. It’s easier to tell someone your skeleton is a Tyrannosaurus than to do what I’ve just done here and explain how there is a similar, but different, tyrannosaur in Mongolia called Tarbosaurus.

So, we can look for anatomical features in the skull and skeleton that indicate whether or not the tyrannosaur was a Tarbosaurus or a Tyrannosaurus. But how do we know that the skeleton came from Mongolia? Well, much like certain animals today are found only in certain places, some dinosaurs were found only in some places and not others. Tarbosaurus has so far only been recovered from the Nemegt Formation, a set of rocks that are only known in the Gobi Desert of Mongolia. If the skeleton is shown to be a Tarbosaurus, and not some other species of tyrannosaur, then the conclusion we must come to without any additional information is that the specimen comes from Mongolia. We can also use the colour and preservation of the bones to identify where the skeleton came from, because different rock units will produce differently coloured fossils (in Alberta, dinosaur bones are often brown or black, and in Mongolia, they are often white or reddish).

If for some reason there was good evidence that the skeleton did not, in fact, come from Mongolia, that would only make the specimen more scientifically important, as it would extend the geographic or stratigraphic range of the genus Tarbosaurus and would give us important new information about that genus.

I had originally hoped to post this second part much sooner, and so much has transpired since my original Tarbosaurus post. I’m particularly pleased to see that a delegation of Mongolians and palaeontologists examined the auctioned Tarbosaurus this week as part of the investigation into the specimen. You can read their report at the Painter Law Firm's website. I also highly recommend this article at the Guardian by palaeontologist Dave Hone, and many thanks to Brian Switek at Dinosaur Tracking for his kind words about my first post in this series.

Literature!

Hurum JH, Sabath K. 2003. Giant theropod dinosaurs from Asia and North America: skulls of Tarbosaurus bataar and Tyrannosaurus rex compared. Acta Palaeontologica Polonica 48:161-190.

Thoughts on Tarbosaurus, Part 1.

Last time I promised photos of our fieldwork here in Edmonton, but then over the weekend the palaeoverse kind of erupted (in a good way) over the auction of a Tarbosaurus skeleton. Go read Brian Switek’s articlefirst if you’re not acquainted with the story.

Because I am insane, I often read the comments sections on news articles about palaeontology. There are a lot of weird and misguided statements in the comments sections of some of the Tarbosaurus auction news articles (e.g. at CNN, USAToday, Wired). Some of these comments make me frustrated, so I figured I’d try to write down my thoughts on some of the most common recurring themes: 1) Paleontologists are just as bad as fossil poachers and/or private collectors because we hoard the dinosaurs all to ourselves and lock them away in cabinets where the public can’t see them; 2) How do we know the tyrannosaur came from Mongolia?; 3) Why does the auction company call it Tyrannosaurus bataar while palaeontologists call it Tarbosaurus?; and 4) Why is fossil poaching such a big deal, anyway? I’m going to address these over a couple of blog posts because for some reason on these topics I am unusually longwinded and the answer to the first question was getting kind of gigantic.

So, to start with: “Paleontologists are just as bad as fossil poachers and/or private collectors because we hoard the dinosaurs all to ourselves and lock them away in cabinets where the public can’t see them.”

I sort of understand where this sentiment is coming from, but unfortunately it is wholly incorrect, and it saddens me that there folks who have become disenfranchised with science in this way. The role of museums is to conserve artifacts for the long haul – not just a few years, not just this generation, but theoretically for hundreds and hundreds and hundreds of years. Museums also facilitate scientific research (thus contributing new knowledge to society), and education (passing new and old knowledge to members of society). Although there are privately-run museums, many museums in Canada are at least partially supported by the government – ie. the Royal Tyrrell Museum in Alberta, the Canadian Museum of Nature in Ottawa, and the Royal Ontario Museum in Toronto. Because these are publicly-supported institutions, their role is to conserve cultural and natural history artifacts for the people, and so the whole concept of fossils being locked away from the public in museums is largely incorrect.

But let’s dig a little deeper (har har). Yes, a lot of specimens are stored in cabinets and rarely seen by the public. This is not because palaeontologists are trying to ‘hide’ specimens, but because at any museum there is limited space and funding for exhibiting specimens. Choosing which specimens go on display involves a lot of factors: is the specimen sturdy enough to be mounted or displayed, does the specimen need to be easily accessible for research, is there enough space to display the specimen, will it require special new cabinetry and lighting, will it require an entire overhaul of the existing displays or can it be slotted into an existing gallery, how much new interpretive material needs to be created, and more. Not all fossils make great display specimens, but that does not mean they are ‘worthless’ or have little scientific value. For example, many studies require the identification and measurement of THOUSANDS of teeth and bone fragments. How else can you know if a particular fossil is rare unless you have a large, unbiased sample? Yes, we could display these tiny fossils, and I actually think that would be a great way to teach the value of large collections of otherwise mundane fossils. BUT given the option of displaying 1000 Paronychodon teeth in a glass cabinet, or one really excellent Albertosaurus skull, it makes sense that the museum would display the showier, more easily relatable object (sorry, Derek). In a perfect world we would not need to make that choice, but in reality there are constraints on what can be displayed based on time, money, and space.

A lot of commenters on the news articles have mentioned that a lot of museums offer ‘backstage tours’ to the collections areas. While this is true, it is also true that many museums require visiting researchers to be professional palaeontologists associated with either a museum or university (or to be a student studying towards that profession). I can’t speak for all museums here, but I suspect that the main reason for limiting visitors to the backstage areas comes back to conservation of the material. A lot of fossils don’t do well with repeated handling, and even gentle handling by careful scientists (or contact with things like metal calipers!) can gradually erode and damage specimens. As such, limiting access to the collections is not really because we want to hoard the fossils and keep them to ourselves, but out of concern for the long-term safety of irreplaceable objects. The flip side of this is that some museums have dedicated teaching and outreach collections of sturdier specimens that can be handled often.

But a lot of these comments seem to come back to a sense of distrust of professional palaeontologists, and perhaps a distrust of the ‘scientific establishment’ as a whole. I don’t really know what to say to this – yeah, there are probably some really awful people who are also palaeontologists, who don’t look kindly on amateur palaeontologists or private collectors, and who may be generally unpleasant people to be around. But there are awful people in every profession. It doesn’t excuse their behaviour, but there’s not necessarily a lot any one of us can do about it. From my experience, the vast majority of professional palaeontologists are just that – professional. They are excited to learn more about life on earth, to contribute to the scientific record, and to educate the public about those findings. They like dinosaurs (or brachiopods, or trilobites, or sabre-toothed cats) SO MUCH that they literally want to spend their entire career thinking about them ALL THE TIME. (There is no escape.) Many of them would love to display more of their fossils, but are unable to because of lack of funding or space. So, if you are really and truly concerned about the lack of public access to fossils, the best thing you can do is go out and support your local museum. Petition your local or provincial or federal government to make museum funding a priority. Participate in fundraisers or organize your own. Donate your time by volunteering as a fossil preparator, or go out into your community and teach others about palaeontology. The worst thing you can do is support the illicit trade of poached, illegally-acquired specimens. And we’ll talk about why in the next post.

(And if you want to help out re: the Tarbosaurus auction, there's a Change.org petition you can sign.)

LogiCON and the Paleo Gala

Fieldwork has begun here in Edmonton and I'll have some more pictures to show off next week...currently we are digging a big hole in the dirt, so there's not much to see yet. Until then, here's a wrap-up of some of my outreach and teaching activities from the last few weeks.

In addition to the Alberta Paleontological Society Symposium, I was asked to give a talk at a local skeptic's conference, called LogiCON. This was a pretty neat event with lots of interesting speakers divided into three 'tracks' - beginner, advanced, and family. I gave both a family-track and advanced-track talk, which may have been a little overly ambitious, but worked out in the end. For the family-track talk, I did "The Wonderful World of Dinosaurs", which was essentially an overview of the kinds of dinosaurs found in Alberta and a little bit about how palaeontologists study dinosaurs. There are lots of well-known Albertan dinosaurs, so I also included some lesser-known taxa like Chirostenotes (using the Smithsonian's caenagnathid mount as a stand-in), Albertonykus (using Mononykus), and the newly-named leptoceratopsids Unescoceratops and Gryphoceratops.

For the advanced-track talk, I thought about talking about dinosaurs as ambassadors of evolution, but didn't really feel like talking about creationism, so instead I opted for "The Dinosaur Family Tree", a talk about...systematics! Complete with data matrix! Woohoo! Actually, this seemed to go over fairly well, as I went through the problems that palaeontologists (and most biologists) face when trying to reconstruct the tree of life: understanding sources of variation, defining a species, and running phylogenetic analyses. And we talked about what makes a dinosaur a dinosaur, as well. The diagram above is based off a specimen on display at the U of A Paleo Museum (UALVP 300, a composite of three individuals), with various dinosauromorph, dinosauriform, and dinosaurian features.

Finally, a few weeks ago I helped organize the annual U of A Paleo Gala, an event hosted by Dr. Michael Caldwell, which raises funds for specimen acquisition, research, and grad student scholarships. It's a fancy dinner held at our faculty club, and the grad students put up posters and show off new specimens and research. There are silent and live auction items much like at SVP, and you can usually count on a song or two by John Acorn, the Nature Nut.

Those of you who were at the SVP in Las Vegas may recognize a few of the larger faces in this crowd... other recent acquisitions largely include specimens for our teaching collection, like casts of Tiktaalik, Anhanguera, Eotitanosuchus (=?Biarmosuchus), and Dinodontosaurus.

Well, that about covers it for now! Next week, the field!

Waking up from hibernation.

And by hibernation, I mean grad school. The last few weeks have been pretty busy here in Edmonton and I've found myself without a lot of time to blog about interesting things that have been going on. Thankfully, that busy-ness is a result of research productivity and teaching, which are both good things! So, over the next few days, as we head into the (still somewhat cold) field season here in Alberta, I'll try to cover a bit of what's been happening for the last couple months...

First up: Alberta Paleontological Society Symposium

I can't believe it's been more than a month already since the APS symposium! The Alberta Paleontological Society is a group of amateur and professional paleontologists from around Alberta, which organizes summer field trips and an annual symposium and workshop series. The symposium is always a good time, and there's usually palaeontology professors and grad students from the University of Calgary, University of Alberta, and Royal Tyrrell Museum (plus often other institutions like the T. rex Discovery Center, Canadian Fossil Discovery Centre, Tumbler Ridge Museum, and Grande Prairie Regional College). This year I gave a talk about my travels in Korea, China, and Mongolia last summer, and was also invited to host a 3-hour workshop the following day.

 

 

Because I was expecting a largely adult audience (rather than families or mostly small children), I had to come up with something a little different than previous dino-workshops I've given. What do you do that's hands-on, not super boring, and not a craft? Well, two years ago I, and my fellow grad student Mike Burns, had given a talk about the frequent (and usually hilarious) misrepresentation of ankylosaurs in the popular media, and it had been a big success. So I decided to run with that. I brought with me a bunch of ankylosaur casts (skulls, a tail club, a foot), and some real fossils (osteoderms, thin sections, teeth), and lots and lots of popular reconstructions of ankylosaurs, mostly in the form of toys (or, uh...scientific models?) and books. These were scattered around the lab, which holds about 20 people.

 

 

 

Over the course of the workshop, I talked for about 10-15 minutes at a time about the anatomy of ankylosaurs, starting with a general overview, then moving on to the skull, skin/armour, tail, and legs and feet. We finished up watching a couple of clips from various documentaries and talking about posture, movement, and behaviour. Each workshop attendee picked 2 or 3 reconstructions to evaluate during the workshop, and had a worksheet to make notes about the anatomy of their reconstructions. After I would talk about some aspect of ankylosaurs, there was 10-20 minutes for looking at specimens, discussing the pros and cons of different reconstructions, and asking questions. Then I'd call everyone back together and ask who had the worst/best reconstructions and why.

If you're ever called to do a dinosaur or paleontology workshop for adults - do this! It was lots and lots of fun. It required fairly minimal preparation, which is a plus if you're often asked to do this sort of thing. I spent a couple of hours at most putting together a powerpoint of mostly specimen images, picking out books and toys and fossils to bring with me, and making up some handouts). It's a great way to engage adult learners, and could probably easily be restructed to work for kids or families as well.

More importantly, I think this might be a really effective way of communicating a lot of information about paleontology in a way that will encourage the general public to look at popular science more critically. Since most people will generally not be going to the primary literature to answer their paleontology-related questions, their information is going to come from illustrated books, magazine

articles, computer animated documentaries, and museum exhibits. If I had just discussed the anatomy of ankylosaurs via presentation and specimens, I'm not sure a lot of the points I discussed would have sunk in as much as they did by critiquing the illustrations and toys most people are likely to encounter. This was an easy way to make a talk more hands-on, and the casual atmosphere and conversation between the workshop attendees was really great.

The next APS Symposium will be held on Saturday, March 16, 2013. The symposium is always held in the Jenkins Theatre at Mount Royal University in Calgary, Alberta.

(Thanks to Angelica for taking some photos of the workshop!)

5 Questions for Aaron Leblanc

It's been a bit quiet around here lately as I plug away at my thesis, but here's an interview with UALVP alumnus Aaron Leblanc, now a PhD student at the University of Toronto. Aaron's description of the new mosasaur Eremiasaurus was published in the January issue of the Journal of Vertebrate Paleontology.

1. What inspired you to conduct this study?

My inspiration for this study comes from my work on an undergrad honors thesis with Dr. Michael Caldwell back in 2007–2008. I remember being shown potential subjects for my project and being drawn to the skull of what is now Eremiasaurus right away. Back then only the left side of the skull was prepared and really didn’t look like much, because most of the elements of the skull had been badly crushed and displaced from their original positions (Al Lindoe did a great job preparing the other side of the University of Alberta specimen, but that didn’t happen until I had started my Master’s thesis on the same subject over a year later). Even at that point you could tell that the teeth of this mosasaur were really unusual. I think the teeth alone were what drew my attention and got this whole project rolling.

2. How does a mosasaur wind up in Morocco?

By the end of the Cretaceous, mosasaurs were everywhere, but this wasn’t the case around 90 million years ago when the first mosasaurs took to the seas. At that point in time, mosasaurs were rather small, occasionally reaching lengths of two meters or so. More importantly, these early mosasaurs were probably still capable of walking on land and may have been restricted to shallow marine habitats. Coincidentally, the early fossil record of mosasaurs is quite restricted geographically. Most of the early mosasaur fossils (a group traditionally called the aigialosaurs) have been recovered from Croatia, Slovenia, and possibly from Texas. If you fast-forward to the Maastrichtian, the time interval from which Eremiasaurus is found, mosasaurs had become incredibly large (some reaching body lengths of 15 meters) and their remains have been recovered from every continent, including Antarctica. The occurrence of mosasaurs in Morocco isn’t a new discovery, but it is certainly becoming an increasingly more valuable data point the more we learn about their diversity and paleoecology during that time and in that particular region of the globe. The Late Cretaceous seas of Morocco were home to some very unique mosasaur taxa that occupied nearly every aquatic predatory niche, from hard shell-crushers like Globidens phosphaticus to (what I believe, anyway) fish-eaters like Eremiasaurus heterodontus.

3. What is special about the tail of Eremiasaurus?

Nobody paid particular attention to the tails of mosasaurs until a recent study of Plotosaurus bennisoni from the Maastrichtian of California by Johan Lindgren and colleagues back in 2007. Their work was incredibly important, because it challenged a traditional view of mosasaurs as resembling giant sea serpents, slithering through the water using side-to-side motions of their whole bodies to move through the water. What Lindgren et al. (2007) were able to show is that there is anatomical evidence that the tails of more advanced mosasaurs were much more specialized for aquatic locomotion than this historical view. The vertebrae at the base of the tail (called pygals) did not allow much side-to-side movement and the bony supports for a tail fin were pushed further back along the body. What this means is that at some point in their evolutionary history, mosasaurs abandoned that slithering style of swimming for a more thunniform (tuna-like) body shape and swimming mode. This represents a more efficient swimming style for cruising the open waters and engaging in pursuits of food, instead of lurking and ambushing. Mosasaur researchers aren’t as lucky as those that study ichthyosaurs (an unrelated group of marine reptiles), because there are no recorded cases of soft tissue outlines of the tails of mosasaurs. While it is only speculative, the current view is that mosasaurs had a crescent-shaped tail fluke like an ichthyosaur or a Great White shark. The vertebral column in well-preserved mosasaur specimens, including Eremiasaurus, has a gentle downward bend that starts just behind the pelvic girdle, and the tall neural and haemal spines (upwards and downwads projections of the tail vertebrae respectively) form a broad sweeping fan at the back of the tail that would have supported an expanded dorsal tail fin made entirely of soft tissue.

Where Eremiasaurus differs from other mosasaurs is in how far back the bony supports of the tail fluke have been “pushed” compared to other species. While it isn’t the most ichthyosaur-like tail ever reported for a mosasaur (though it is a close second), it still suggests that it adopted a more thunniform style of swimming than most other related forms.

4. What is unusual about the teeth in Eremiasaurus?

The teeth are certainly the most conspicuous features of the skull of Eremiasaurus. I always imagined it having a fiendish grin, especially when looking at the right side of the skull of the University of Alberta specimen. The teeth are unusual in that they change shape so dramatically along the length of the jaws and along the roof of the mouth (mosasaurs had a second row of upper teeth that lined the pterygoid bones, just for good measure). The front teeth are straight and cone-shaped,

the middle ones are slender triangular blades,

and the back teeth are more bulbous and hooked.

Whatever Eremiasaurus was eating, it was very good at tearing it apart into smaller more palpable pieces. The front teeth interlock when the jaws are closed, making for an efficient trapping mechanism, while the middle and back teeth are serrated and shear past each other like a pair of scissors to cut and dismember prey. The pterygoid teeth are curved backwards and would have kept struggling prey in the mouth. From an evolutionary perspective, attributing these kinds of teeth, tail anatomy and other unusual features of the skull to anything but a new genus and species was all too difficult.

5. What does Eremiasaurus tell us about the relationships among mosasaurs?

Adding Eremiasaurus to an existing phylogeny of mosasaurs added a great deal more complexity to the story, particularly within the subfamily Mosasaurinae (the group to which Eremiasaurus belongs). In many ways Eremiasaurus is an intermediate between two well-established groups of mosasaurines, something that was clear from the first phylogenetic analysis we performed. Where these relationships became more complex was in a second analysis in which we added and updated information to the existing data set. We performed this second analysis, because many of the characters and species of mosasaurines that were originally used back in 1997 by Gordon Bell were in need of revision. New species had been described since then and had not incorporated into such an analysis, while others had since been re-examined and re-described. Using this updated data set, we were able to conclude that many of the features previously thought to be diagnostic for one of the major groups of mosasaurines were actually present in most of the members of the other group as well, or were secondarily lost. Because of this, many of the previously well-established relationships within the subfamily Mosasaurinae broke down in this analysis, suggesting that there is a need to reconsider some of our classifications, or re-evaluate the characters that we use to define them.


Thanks Aaron! You can read more about Eremiasaurus in:

Leblanc ARH, Caldwell MW, Bardet N. 2012. A new mosasaurine from the Maastrichtian (Upper Cretaceous) phosphates of Morocco and its implications for mosasaurine systematics. Journal of Vertebrate Paleontology 32:82-104.

Gobi Desert Diaries: Nemegtomaia Edition

Today I've got five questions for Federico Fanti, the lead author on a paper published a few weeks ago in PLoS ONE on a nesting oviraptorosaur. I first met Federico during the 2007 Nomadic Expeditions Dinosaurs of the Gobi expedition, in which we all had a grand time prospecting for dinosaurs and during which we celebrated a fine discovery indeed.

1. What inspired you to conduct this study?

Well, the fossil itself! I grew up with incredible pictures taken somewhere in the Gobi Desert of Mongolia, with spectacular fossil remains literally emerging from the vermillion sand. When Phil Currie and I realized that we were looking at a nesting dinosaur we were simply happy and enthusiastic: there are only 5 specimens of brooding dinosaurs known to date in the world, it is a unique find. I couldn't wait to find out more about this specimen and finally, after more than four years, I'm glad to see the paper out.

 

(MPC-D 107/15 diagram from Fanti et al. 2012, by Marco Auditore.)

2. Nemegtomaia is not exactly a household dinosaur name. Who is Nemegtomaia?

Nemegtomaia means "good mother of the Nemegt" and curiously the name was chosen long before our discovery. In the '90s, the type specimen - including a nicely preserved skull - was collected from the Nemegt Formation not far from where we found the nest: however, no trace of eggs or nest were found at the time. The discovery of MPC-D 107/15 (or Mary, as I still like to call it) definitely supports the choice of Nemegtomaia as the name for this species. Nemegtomaia is a genus of oviraptorid dinosaur that inhabited what is today southern Mongolia during the late Cretaceous period, approximately 70 million years ago. It is characterized by a well-developed crest on the skull and relatively short forelimbs with robust claws.

(Nemegtomaia skeleton reconstructions from Fanti et al. 2012, by Marco Auditore.)

3. What's so special about MPC-D 107/15?

Unlike all other nesting dinosaur that have been discovered so far, this specimen has a nicely preserved skull and therefore it was possible to reliably refer MPC-D 107/15 to the genus Nemegtomaia. Furthermore, within the context of the Nemegt area where dinosaur eggshells are frequently recovered, it was possible to refer a specific egg type to this genus. In addition, the preservation of the forelimbs allowed us to reconsider the classification of this genus within the oviraptorosaurs: unlike many other oviraptorid species, in fact, Nemegtomaia has relatively short and robust forelimbs, indicative of different adaptations and behavior.

4. In the acknowledgements section of the paper you note that MPC-D 107/15 was excavated 'under what were at times difficult circumstances'. How did you find this specimen, and what were the challenges in excavating it?

I found the specimen while prospecting in a sayr, a canyon located not far from the Camp. It was barely cropping out from a vertical cliff, about 3 feet from the valley ground. A section of the nest and of the pelvis was visible at the time, meaning that, with the exception of the tail, the skeleton was still preserved in the cliff.

(Federico did well to spot the nest, which was hardly exposed at all in the surface - just eggs and legs in cross section.)

It took a full week and the work of several people to take it out, and I must thank all the people that participated in the 2007 fieldwork (including the author of this blog! [aw, shucks - VMA]) for the help in the field.

Difficult circumstances? A mix of heavy rain, collapsing blocks of sandstone alternated with 45 degrees in the shadow are .. interesting circumstances!

(Although I didn't spend much time working on the nest excavation, I do know what Federico, Phil, and Badam are referencing when they say 'difficult circumstances'. On the second-to-last day in Nemegt, the skies opened and it poured rain ALL DAY. The nest had to come out the next day, so a team went out to the site and worked under a tarp all day in the soggy, soggy desert.)

5. What does this specimen tell us about the nesting habits of oviraptorosaurs?

Nemegtomaia has been collected in both the Baruungoyot and Nemegt formations, which are representative of aeolian/desertic and fluvial environments respectively. This indicates that Nemegtomaia was a long-living genus and adapted to different environmental and climatic conditions. The nest preserves approximately 20 eggs: we know from other spectacular specimens of oviraptorid dinosaur that they were able to laid 2 eggs at time, thus we assume that different individual laid their eggs in a single nest. As a consequence, the animals that we discover in brooding position are not necessarily the parents nor the mothers. It is possible that a male was "selected" for parental care during early development of embryos.

If you haven't yet read Fanti et al. (2012), go get it right now for free from PLoS ONE! Thanks Federico!

Fanti F, Currie PJ, Badamgarav D. 2012. New specimens of Nemegtomaia from the Baruungoyot and Nemegt Formations (Late Cretaceous) of Mongolia. PLoS ONE 7(2): e31330.

Cool Stuff

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

The University of Alberta Laboratory for Vertebrate Paleontology contributed fossils from our Grande Prairie and Edmonton dinosaur bonebed excavations. Although we usually collect stuff in the summer, we've had snow during our Edmonton fieldwork, even in May.

We showed off some field jackets, too. The Monoclonius and ornithomimid are pretty self-explanatory, and if I recall correctly, "Skull B" is from the Wapiti bonebed in Grande Prairie. There were also photos from our December tyrannosaur helicopter lift in Dinosaur Provincial Park, including a photo taken by me!

Last spring we purchased a cast of the Cryolophosaurus original non-reconstructed skull for both teaching and research, but it fit in perfectly with the exhibition theme! The grey slab behind the skull is the Wonder Block from the MOTH locality, which has a variety of 'jawless fish'. Phil will be giving a talk about his 2011 Antarctic expedition on March 1, as part of the exhibition's speaker series.

The exhibition also features specimens from our zoology collections, including these Arctic and sub-Arctic mammals (caribou, deer, and walrus).

"Cool Stuff" mixes natural history objects with cultural heritage objects, and in particular I was pleased to see so many Inuit and Inuvaliut art pieces. I am always astounded by whalebone sculptures like this one.

Another display had Inuit dolls, musical instruments, hunting tools, and boots. The beautiful paintings in the background are the original art from Ted Harrison's "A Northern Alphabet". Click the photo to make it bigger, and see if you can figure out what letter each painting represents.

"Cool Stuff" is open until March 4, and admission is free. It was cool, go check it out.