Nanuqsaurus: Beast of the Week

This week we shall be checking the arctic dinosaur, Nanuqsaurus hoglundi!  Nanuqsaurus was a tyrannosaurid, closely related to Tyrannosaurus, Tarbosaurus and Lythronax, that lived in what is now Alaska, North America, during the late Cretaceous period, about 69 million years ago.  Even though only parts of the skull, a few teeth, and a few other bones have been discovered, it can be estimated that Nanuqsaurus would have measured roughly 22 feet (6.7m) long from snout to tail when alive.  Like all known tyrannosaurids, it would have been a meat-eater.  The genus name, Nanuqsaurus, translates to "Polar Bear Lizard" because it was discovered in Alaska...where Polar Bears live.  


When Nanuqsaurus' fossils were initially published on in 2014, it was described as a "dwarf tyrannosaur" with an adult size estimate at about 18 feet long.  The thinking behind this was that since it lived at a higher elevation in an environment that was at least seasonally colder parts of the year, a smaller size would have aided it in requiring less food to stay alive, especially in the winter, when prey was likely more scarce.  A more recent study, however, suggests Nanuqsaurus was at least a little larger, more like 22 feet long, possibly even closer to 30 feet long as an adult, due to the observation that the original fossil material was likely from a juvenile that wasn't done growing at the time of its death, plus additional teeth found that were clearly from a larger animal.

Nanuqsaurus watches as a family of Edmontosaurus pass through.  Watercolor reconstruction by Christopher DiPiazza

A common misconception is that since Nanuqsaurus was found in Alaska, it must have been adapted to extremely cold temperatures, often depicted by artists with a thick coat of snow white feathers trudging through an icy wasteland.  This would make sense if Alaska was exactly the same during the Cretaceous as it is now...except it almost certainly wasn't.  During the Cretaceous, the global temperature was much warmer than it is today, so even the poles would have been noticeably greener.  That being said, what is now Alaska still would have been coolER at the time, experiencing definite colder seasons during winter and fall months, but probably with only occasional snow.  One thing about that environment that was consistent to today, however, was how the poles would have experienced extended periods of daylight in the summer and extended periods of darkness in the winter.  So winter still would have been challenging for most dinosaurs.    

The known remains of Nanuqsaurus from the paper by Fiorillo and Tykoski.  Despite the fact that it isn't much, they were able to determine after close examination that this is indeed a new genus and species of tyrannosaurid.

So how did a dinosaur like Nanuqsaurus survive in a cooler environment when tyrannosaurids elsewhere at the time thrived in more tropical climates?  We know that tyrannosaurs belonged to the broad branch of dinosaurs called, coelurosaurs, many of which were discovered with feathers.  It is therefore totally plausible to infer that all tyrannosaurs had at least some feathers. (Yes, even T. rex.)  Maybe Nanuqsaurus happened to have a denser coat of feathers for better insulation, much like birds in the arctic do today?  

Nanuqsaurus' size may have helped keep it warm as well.  An animal with a larger body has less surface area to volume ratio and therefore more heat conservation.  This is called Bergman's Rule.  You can see examples of Bergman's Rule today in the largest modern reptiles, like crocodiles, which can remain active for longer periods of time without direct access to heat than smaller kinds of reptiles like most lizards/snakes.  In fact, there is another dinosaur known from Nanuqaurus' habitat, a still unnamed species of troodontid, that was the largest known member of its typically small-bodied family, which probably evolved that way for the same reason.  

Animals that live in colder environments also often have shorter limbs and other extremities, which helps prevent as much heat from leaving the body as possible, called Allen's Rule.  We don't have much of Nanuqsaurus' skeleton past the jaws, but it wouldn't be unreasonable to guess it may have had a stockier build for this reason.  

Allen's Rule states that animals typically evolve shorter limbs and extremities to better adapt to consistently colder environments, as demonstrated with the cold adapted, Arctic Fox (Vulpes lagopus) compared to the more generalist, Red Fox (Vulpes vulpes).

When alive, it is likely Nanuqsaurus was the top predator of its environment.  It would have shared its habitat with the large ceratopsian, Pachyrhinosaurus perotorum, and the hadrosaur Edmontosaurus, and probably at least hunted their young.  It also crossed paths with the unusually large (but still smaller than it) Troodon species mentioned earlier, plus at least two kinds of dromaeosaurs.  

That is all for this week!  Feel free to comment below!

References

Druckenmiller, Patrick S.; Erickson, Gregory M.; Brinkman, Donald; Brown, Caleb M.; Eberle, Jaelyn J. (2021-08-23). "Nesting at extreme polar latitudes by non-avian dinosaurs". Current Biology. 31 (16): 3469–3478.e5.

Fiorillo, A. R.; Tykoski, R. S. (2014). "A Diminutive New Tyrannosaur from the Top of the World". PLoS ONE 9 (3): e91287. doi:10.1371/journal.pone.0091287.

 Fiorillo, Anthony R.; Gangloff, Roland A. (2000). "Theropod teeth from the Prince Creek Formation (Cretaceous) of Northern Alaska, with speculations on Arctic dinosaur paleoecology". Journal of Vertebrate Paleontology 20 (4): 675–682. doi:10.1671/0272-4634(2000)020[0675:TTFTPC]2.0.CO;2.

Rhinorex: Beast of the Week

This week we're checking out Rhinorex condrupus!  

Rhinorex was a plant-eating dinosaur that lived in what is now Utah, USA, during the late Cretaceous Period, about 75 million years ago.  It was a hadrosaurid, in the same family as other broad-billed duck-billed dinosaurs like Maiasaura, Edmontosurus, and Hadrosaurus.  From snout to tail Rhinorex would have measured about 30 feet (9m) long.  The genus name, Rhinorex, translates to "Nose king" in reference to this dinosaur's large, down-turned snout.  Other hadrosaurs had similarly-shaped snouts, but none as extreme as Rhinorex's.  When alive, Rhinorex would have lived nearby other dinosaurs such as Coahuilaceratops, Teratophoneus, and its close relative, Gryposaurus.

Watercolor life reconstruction of Rhinorex by Christopher DiPiazza

It's still not clear as to why some hadrosaurs, like Rhinorex, had such downturned snouts.  They may have been an adaptation for a specific feeding strategy, or possibly a display for attracting mates or intimidating rivals.  It may have even enabled Rhinorex to make certain sounds.  Lambiosaurine hadrosaurs like Parasaurolophus, possessed crests that grew from their snouts, but often extended to the tops of their heads for display and sound purposes.  It is possible that the lineage Rhinorex was from just applied the strategy in a different direction. 

Reconstruction and photograph of Rhinorex skull.  Image from the paper by Terry Gates and Rodney Scheetz.

Rhinorex was the only well preserved dinosaur fossil found from its specific area thus far.  In addition to it's skull there was also some skin impressions found, which look similar to other known hadrosaur skins; fine pebble-like scales.  All other dinosaur fossils in Utah from the same time period were found hundreds of miles away and would have likely been adapted to at least a slightly different kind of habitat.  Rhinorex helps fill in gaps previously unknown about Late Cretaceous ecosystems in Utah. 

That's all for this week!  As always feel free to comment below or on our facebook page!  Have a request?  Just let me know and I'll make it happen!

References

T.A. Gates & R. Scheetz (2014): A new saurolophine hadrosaurid (Dinosauria: Ornithopoda) from the Campanian of Utah, North America Journal of Systematic Paleontology. doi: 10.1080/14772019.2014.950614

Tianyulong: Beast of the Week

This week we'll be checking out a fascinating little creature that changed the way we imagine dinosaurs.  Let's get to know Tianyulong confuciuci! 

Tianyulong was a plant-eating (or maybe omnivorous) dinosaur that lived in what is now Northeastern China, during the late Jurassic period, between 158 and 159 million years ago.  It was tiny, only measuring a little over two feet long from beak to tail. (about 70cm) The genus name translates to "Tianyu Dragon", named after the Tianyu Museum of Nature, where the first discovered skeleton of this dinosaur is housed. 

Tianyulong life reconstruction in watercolors by Christopher DiPiazza.

Tianyulong was a member of the heterodontosaurid family of dinosaurs.  Heterodontosaurids were small, plant-eating or possibly omnivorous, dinosaurs that flourished during most of the Jurassic period.  They are widely thought of being from the base of the ornithiscian branch of dinosaurs, which later includes ceratopsians (like Triceratops), ornithopods (like Iguanodon), and the armored thyreophroans (like Stegosaurus and Ankylosaurus).  More recently it was suggested that heterodontosaurids were more closely related to marginocephalian dinosaurs (group that includes more ceratopsians and pachycephalosaurs) than other ornithiscians.

We know more about what Tianyulong looked like in life, compared to most prehistoric animals, because there are more than one full skeletons on the fossil record.  Tianyulong had a proportionally large skull and short neck.  It also had very long legs with long foot bones, implying it was a fast runner in life.  The tail was more than double the length of the rest of the body.   

Cast of the holotype of Tianyulong on display at the American Museum of Natural History in New York in the temporary Dinosaurs Among Us exhibit.

In its skull, Tianyulong had small flattened teeth in the back of its jaws that appear to have been ideal for shearing plants.  In the front of its mouth, just behind its beak, it had two pairs of long canine-like teeth, a trait present in all known heterodontosaurids.  It is still unclear as to exactly why this unusual trait evolved, especially in small plant-eating dinosaurs.  It is also worth noting that individuals that appear to have been not fully mature still have these long teeth, so they may not have been an adaptation for sexual selection.  There is also no evidence they were only present in one sex and not the other.  Some have suggested they had something to do with the dinosaur's diet.  Others have suggested that both males and females could have used these teeth to participate in intraspecies combat or display over territory.   

Tianyulong skeleton, including the outline of feathers, currently at the Beijing Museum of Natural History.  Note how most of the body is covered in feathers.  Also check out that cute tail tuft!

Possibly the most amazing thing that we know about Tianyulong is the fact that many of the skeletons found preserved feathers! The exact arrangements of these feathers varies slightly among the known individuals, but they all at least appear to have had long bristle-like structures growing from their backs.  One individual also shows a shorter, but extensive coat of feathers over most of the rest of the body with a tuft of longer feathers at the tip of the tail.  Another still undescribed individual (mentioned by paleontologist, Dr. David Hone) had what appears to be the long bristles in a mohawk arrangement running from the head down almost the entire length of the animal's body.   It is possible these variations could be based on the sex or maturity of the animals. It's also possible they all looked the same in life but fossilized in different stages of decomposition, resulting in some with more feathers than others. Regardless, the presence of these feathers on Tianyulong, an ornithiscian dinosaur and not a theropod (dinosaur group that includes birds), strengthens the argument that feathers may have been more extensive among dinosaurs than originally thought.  

References

Butler, Richard J.; Smith, Roger M.H.; Norman, David B.(2007). "A primitive ornithischian dinosaur from the Late Triassic of South Africa, and the early evolution and diversification of Ornithischia". Proceedings of the Royal Society B: Biological Sciences. 274 (published online): 2041–6.

Butler, Richard J.; Upchurch, Paul; Norman, David B. (2008). "The phylogeny of the ornithischian dinosaurs". Journal of Systematic Palaeontology. 6 (1): 1–40. 

Liu Y.-Q. Kuang H.-W., Jiang X.-J., Peng N., Xu H. & Sun H.-Y. (2012). "Timing of the earliest known feathered dinosaurs and transitional pterosaurs older than the Jehol Biota." Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication).

Zheng, Xiao-Ting; You, Hai-Lu; Xu, Xing; Dong, Zhi-Ming (19 March 2009). "An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures". Nature. 458 (7236): 333–336.

Dissecting a Dinosaur with Divya Anantharaman

Almost a year ago I teamed up with my friend, Divya Anatharaman, award-winning taxidermist, to present a live webinar showcasing bird anatomy and how they relate to extinct dinosaurs.  Divya dissected a young rhea (bred in captivity and died of natural causes) up close on camera, giving viewers insight into bird anatomy they may otherwise never get to see, while I discussed how these bird features can also be seen in long extinct dinosaurs.  If you missed this amazing event, I finally have the full video uploaded for you enjoyment!

If you have not already, please visit Divya's website, Gotham Taxidermy, and keep an eye out for more webinars in the future!

Sinraptor: Beast of the Week

Sinraptor was a large meat-eating dinosaur that lived in what is now Northwestern China during the late Jurassic period, about 160 million years ago.  From snout to tail it is estimated to have measured 29 feet (7.6 meters), although some suggest it may have been able to grow longer.  The genus name translates to "Chinese Thief".

Sinraptor belonged to the family of theropod dinosaurs called the metriacanthosaurids, which are relatively closely related to popular dinosaurs, like Allosaurus and Giganotosaurus.  Metriacanthosaurids were relatively large meat-eaters that reigned between the middle Jurassic to the early Cretaceous periods in the northern hemisphere.   Metriacanthosaurus, which has also been reviewed on this site, was another member of this family, and close relative of Sinraptor.

Sinraptor dongi chasing a pack of the early tyrannosauroid, Guanlong, off of a kill.

Sinraptor had a relatively deep laterally compressed skull that had jaws lined with long, blade-like teeth.  This seems to have been an adaptation for slashing large chunks of flesh from the bodies of other animals. It had short, powerful arms, that ended in three fingers tipped with hook-shaped claws, which also may have aided in feeding or hunting.  Sinraptor also possessed bony ridges over its eyes and snout which would have had horny keratin growing from them life.  This was likely an adaptation for communicating with, or perhaps even fighting, members of its owns species.

Sinraptor skull on display at the Zigong Dinosaur Museum, in Sichuan, China. (Photo credit: Zhangshugang)

Sinraptor was likely the top predator of its community, and may have used its size and formidable weaponry to hunt large sauropods and stegosaurs it shared its habitat with.  It also coexisted with the much smaller early tyrannosauroid, Guanlong, which probably avoided Sinraptor whenever possible.

References

Carrano, M. T.; Benson, R. B. J.; Sampson, S. D. (2012). "The phylogeny of Tetanurae (Dinosauria: Theropoda)". Journal of Systematic Palaeontology. 10 (2): 211–300.

Currie, Phillip J.; Zhao, Xi-Jin (1993). "A new carnosaur (Dinosauria, Theropoda) from the Jurassic of Xinjiang, People's Republic of China". Canadian Journal of Earth Sciences. 30 (10): 2037–2081.

Interview with Paleontologist: Rhiannon LaVine

Dr. Rhiannon (Rhi) LaVine is an invertebrate paleontologist who is an NIH-IRACDA postdoctoral fellow in the Biodiversity Institute at the University of Kansas. Her research interests revolve around questions relating to the mechanisms that generate and influence patterns of morphological diversity in organisms and how that shapes their evolutionary trajectories. She is particularly interested in exploring this topic using fossil arthropods such as trilobites and trilobite-like animals. Rhi received her Ph.D. from the University in Chicago where she began this line of research using agnostine arthropods. Prior to graduate school, she received her B.S. from the University of Wisconsin - Whitewater where she investigated the response of gastropod faunas to the end-Permian mass extinction both in her undergraduate research and through the Natural History Research Experiences (NHRE) internship program hosted at the National Museum of Natural History, Smithsonian Institution in Washington D.C.

Rhi with an assortment of fossils

Question 1: What was your earliest sign of interest in paleontology that you can remember?

RV: Doesn’t everyone around my age say, “Jurassic Park”? I hate to say that I’m not much different in that respect. Before the film was released, my late father read the book and shared it with me when I was around 7 or 8 years old. He was also a substitute teacher at the time and (hilariously) read passages of it to some of his classes---namely the gruesome Nedry vs. dilophosaur scene, which was our favorite. It was one of the many things over which my dad and I bonded, and following the film’s release (which we saw in theaters), I had my big ol’ dinosaur phase that just about every kid goes through. That led to a deeper interest in fossils and geology which, unfortunately, became somewhat stifled as I became more recognized for my artistic talents instead of my academic interests. Thankfully I was in the right place at the right time in college to have that passion reignited.

 

Question 2: Did you have anyone who served as a role model when you were younger?  Do you still have any now?

RV: I am my father’s daughter and have always looked up to him. He was someone who never hesitated to chase his dreams (even the ridiculous ones that took him out to LA to be a drummer) and stand up for what was right. He was a much-loved high school teacher who served as inspiration to many and a kind ear to all. I’ve always said that if I end up being half as good of an educator as he was, my career will have been successful.

More recently I have been lucky enough to learn quite a bit from Sue Kidwell, whose career of pioneering work has really shaped how we address and ask questions of the fossil record. I can honestly say that she is an inspiration, especially when it comes to maintaining the drive to continue pushing against the status quo in our field.

Question 3: You primarily work with invertebrates.  Tell us more about your work and what it's all about. 

RV: The first thing that I was asked in grad school was “what’s your question?”, which was a not-so-subtle hint that I should divorce myself from focusing on a particular study organism and think about questions that could be applied broadly. That being said, my work gets at questions relating to how patterns of morphological diversity are generated. Heritable variation is the raw material upon which natural selection acts, after all. I’m interested in figuring out what causes that variation and how, if at all, it scales up to trends that we see at the macroevolutionary level. I tackle this using geometric morphometric methods, meaning that I rely on shape data. As for the system, it just so happens that marine invertebrate fossils, specifically arthropods, are ideal because they preserve very well (often minimally-distorted) and there are a lot of them (allowing for good sample sizes). As an example of the sort of work that I like to do, for my dissertation I worked with agnostine arthropods, which are tiny, blind, trilobite-like critters. I measured them in a way that would reveal developmental constraints on their form, which could indicate long-term constraints on morphological diversity in this group of organisms as a whole. The current work that I’m doing in my postdoctoral position doesn’t get at the generation aspect of variation, but instead explores the extent of morphological variation in a group of trilobites and how it manifests phylogenetically, biogeographically, and through time.

Left: an agnostine arthropod cephalon (head) mounted on the tip of a toothpick. Right: Landmark and semilandmark configuration for geometric morphometric analyses.

Question 4: Was there anything you did or learned as you were on your way to your current career that you feel got you to where you are?  What sort of field experience, a class, networking with the right people, or possibly something different?

RV: I would say that networking and early research experience were the key elements. I often talk to prospective undergraduates who are worried that if they don’t go to a big name school, their hopes and dreams of becoming a paleontologist will be dashed. Well, here I am with my start in a relatively small undergraduate institution and I somehow stumbled upon this career. I firmly believe that I got to where I am because my undergraduate advisor pushed me to network and get involved in research early on. I went to and presented at GSA and other conferences, talked with other students in my field, reached out to potential advisors, and I was generally enthusiastic and active in the geoscience community. I feel as though if I did go to a bigger school for my undergraduate degree, I may have been just another face in the crowd. The fact that I did go to a small school provided me with the opportunity to receive more direct mentorship and guidance.

 

With colleague and “trilobite twin” Matt Witte at GSA

Question 5: What would your advice be to anyone trying to make a career in paleontology (or science in general)

RV: Get involved in research as soon as you’re able to do so. Even if you’re in high school, contact your local club to see if there are any outings that you can join. Reach out to paleontologists at a nearby museum or university to volunteer to help with their collections or, even better, see if they need someone to do some otherwise tedious fossil counting/measuring for a project. Get your hands dirty and make yourself visible to those who are in the field of study that you’re aiming to pursue.

Question 6: What was or is your favorite project so far? (geology or paleontology)

RV: My favorite project is not so much a project as it is a long-term endeavor that focuses on figuring out what’s going on in a particular unit called the Spence Shale: a middle Cambrian Lagerstätte on the border of Utah and Idaho. Not only does it contain a wide array of complex and, frankly, weird preservational environments, but it is bursting with such diverse and amazingly-preserved fossils, many of which remain undescribed. I started working on this unit near the beginning of my dissertation, specifically targeting the agnostoid fauna. Later on my colleague, Julien Kimmig, spearheaded the bulk of the work on this unit. Now, with help from L.J. Krumenacker (who we temporarily coaxed over from the vertebrate paleo side), we are hopefully beginning to put the pieces of the Spence puzzle together.

Rhi (center) with colleagues L.J. Krumenacker (left) and Julien Kimmig (right) after trenching the type section of the Spence Shale.

Question 7: Do you have a favorite destination when it comes to fossils?  Why?

RV: A a perfect continuation from the previous question: my favorite destination is Spence Gulch, the type section of the Spence Shale. It’s an idyllic little stream cut within a forest in Idaho. It’s quiet, scenic, and one can just spend the entire day easily splitting apart the rocks to find bountiful and beautiful fossils. This site really spoils you. I’m pretty certain that if it was someone’s first fossil-hunting site, it’d ruin them for any other site because the bar would be set so high. I’ve not encountered too many other places like it.

Views of Spence Gulch

Question 8: A popular image of paleontologists is that they are constantly out in the field digging up fossils, which is true sometimes  What people don’t realize is that a lot of paleontology work is conducted in a lab as well.  In your experience how much time have you spend in the lab and in the field?  What do you prefer?

RV: For me it’s about 10% fieldwork and 90% “in the lab”. Of course, “in the lab” means a lot of things: in the lab prepping/sorting fossils, rifling through museum collections, sitting behind a computer running analyses, doing literature reviews, etc. I wish I could justify more fieldwork in my research. There’s really nothing comparable to getting out there, cracking open a piece of shale, and finding something new that no one has ever laid eyes on. “Lab” work is the price I pay to be able to go out into the field from time to time.

 

Question 9: Are there any fossils you’d like to work with that you haven’t yet?

RV: I would love to work on insect fossils! Unfortunately I can’t think of too many questions that both pique my current interests and that the fossil record of insects can reasonably accommodate.

 

Question 10: Do you ever get criticized on any of your work?  How do you handle it?

RV: Don't we all? In my experience thus far, the vast majority of my colleagues are wonderful people who offer criticism in a helpful manner. I have encountered people who get possessive over their study system of choice and are on the lookout for anything to pick apart, though. I’d like to say that I handle it with the practiced grace of a respectable academic, but my inner (outer?) punk tends to get riled up. I usually end up taking a deep breath, stopping myself from being confrontational, and reminding myself that it comes with the territory.

 

Question 11: A common idea is that paleontology is just a “for fun” science, with no real impact or noticeable effect that helps the world.  Do you think paleontology has a bigger part to play to than this?  How?

RV: One of the main things that I try to drive home with all of my students (or even just people with a passing interest in what I do) is the absolute vastness of deep time, and I think that’s something that we can only begin to wrap our heads around via the study of paleontology. It’s easy for someone to rattle off numbers associated with absolute ages of the earth without actually understanding what that number means. It’s also pretty easy to look at all of the life forms that exist today and think that’s all we need to consider in order to understand the natural world.  By contrast, when you’re able to incorporate the fossil record, you’re able to begin to understand how life has emerged and changed over enormous spans of time, resulting in the mind-blowing diversity that we see today. Suddenly we’re able to start to piece together the puzzle of how modern biodiversity came to be within that structure of seemingly unfathomable vastness of time.

Collecting from Miners Hollow in the Wellsville Mountains

Question 12: Who was the first paleontologist you met?  How was that interaction?

RV: Rex Hanger, professor at the University of Wisconsin - Whitewater. At the time, I was an art major who was severely dissatisfied with my program and career path. As a lark, I took the Geology 204: Earth and Life History course because I’d always had an interest in geology and paleontology, but I never really saw myself as a STEM person. Rex made the subject incredibly accessible and thus I came to the realization that I could maybe pursue paleontology as a career. I approached him one day after class and told him that I was considering changing my major to geology. I will never forget the big smile on his face---of course, I probably would have grinned too if a weird, tattooed kid in a tattered Bauhaus shirt came up to me and asked me to be their advisor. From that moment on he became my mentor, immediately plugging me into a research project and setting me on the trajectory that led me to where I am now.

 

Question 13: What is your favorite prehistoric animal?  Was it different when you were younger?

RV: Oh dear, can I pick one from each phylum? I’m probably expected to pick a trilobite, so in that vein I’ll choose Zacanthoides typicalis. It’s a somewhat common trilobite found in my favored field site, but even so I always get excited when I find one. They’re so charismatic! I refer to this group of trilobites as “the punk rockers of the Cambrian trilobite world” for a reason. When I was a kid, I was into dinosaurs and, of course, I was enamored with the “velociraptors” from Jurassic Park. I wasn’t even really deterred when I found out that Velociraptor sp. was, by comparison, a puny little thing. I thought it was even cooler that it was a knee-high terror.

 

Question 14: If you could use a time machine to go back and pick only one prehistoric animal to bring back from history and observe alive and in person, which would it be and why?

RV: Opabinia regalis because, well, just look at that thing! What was it even doing?!

 

Opabinia regalis watercolor by Christopher DiPiazza

Question 15: Back to the time machine.  This time you can go back to any place and time period and have a look at what the environment was really like.  Which one would you pick and why?

RV: The ​Cambrian, of course! I may have a bit of a bias, but being able to see that comparatively alien world in action would be extraordinary

Question 16: Which is your favorite museum?  Why?

RV: I ​will always have a soft spot for the Field Museum of Natural History in Chicago. It was the first big museum that I ever visited. In fact, I found a picture of me as a kid with Bushman the Gorilla and recreated the picture over 30 years later before I left the city for my current position

The Evolving Planet exhibit is a wonderful walk through earth’s history. There were many days that I would visit it and space out to the soothing sounds of the Cambrian seascape.

Rhi and Bushman at the Field Museum, over 30 years in between.

Question 17: What hobbies do you have?  (Don’t have to be paleo-related.)

RV: I definitely make an effort to keep a work-life balance, which means that my hobbies are not related to paleontology. When the weather cooperates I get outdoors to go running or hiking; the latter of which usually involves me taking my camera along so I can dive into the underbrush and take photos of neat insects and such. I am also an avid curler (the sport, not the hairstyling). Beyond it just being great fun and challenging, I’ve met some of the coolest people in the curling community. It’s a sport with a foundation in good sportsmanship and camaraderie---I highly recommend that anyone who has ever had even a passing interest to try it out if they can. Finally, no shame: I’ll admit that I get really into tabletop games such as Dungeons & Dragons and Vampire: the Masquerade. I always play a ranger in the former and Clan Brujah in the latter.

Lambeosaurus: Beast of the Week

 This week we will be checking out another amazing hadrosaur.  Make way for Lambeosaurus!

Lambeosaurus was a hadrosaur ("duck-billed" dinosaur) that lived in what is now Canada during the late Cretaceous period, 75 million years ago.   Adults measured 23 feet (7 meters) long from beak to tail.  The genus name translates to "Lambe's Lizard" in honor of the paleontologist, Lawrence Lambe.  Like all hadrosaurs, Lambeosaurus would have eaten plants when alive.

Lambeosaurus lambei life reconstruction in watercolors by Christopher DiPiazza.

Lambeosaurus was a member of the lambeosaurine group of hadrosaurs, which are characterized by having more narrow snouts and often elaborate, hollow, bony crests on their heads.  Corythosaurus and Hypacrosaurus are two other members of this group which were particularly closely related to Lambeosaurus.  Within the Lambeosaurus genus there are actually two distinct species, Lambeosaurus lambei and Lambeosaurus magnicristatus.  Lambeosaurus lambei was discovered first, lived earlier by a few million years, and had a crest that jutted out in the front accompanied by a solid, bony, rod-like structure growing out of the back of its head.  Lambeosaurus magnicristatus lived slightly more recently, and had a larger, rounder crest that grew forward out of the top of its skull. 

There are two species of Lambeosaurus.  Lambeosaurus lambei (left) and Lambeosaurus magnicristatus (right). 

The exact function of Lambeosaurus' crest may always be a mystery, but many experts agree it most likely evolved for some sort of display within the species.  The front portion of the crest was also hollow, and attached to the nasal cavities of the animal, so it is commonly suggested they had a role to play in making unique sounds, as well.  Among Lambeosaurus lambei specimens, there seems to be a variety in crest size between individual adults.  Some paleontologists believe that this represents sexual dimorphism, the males with slightly larger crests than the females.  Babies and juveniles are also known from Lambeosaurus, which had tiny crests that start in the front of the skull, and expanded backward as the animals matured. 

Skull cast of Lambeosaurus lambei on display at the Academy of Natural Sciences in Philadelphia.

Lambeosaurus had a very long, slender snout that was tipped with a rounded bill.  This feature would have been ideal for clipping tough vegetation that would then be ground up by many small teeth in the back of the mouth, which acted together as a unit, called a dental battery.  Like all reptiles, Lambeosaurus would have been able to regenerate teeth continuously as they became worn or lost.  

Baby Lambeosaurus skull on display at the Royal Tyrrell Museum. (photo credit: Roland Tanglao)

Like all hadrosaurs, Lambeosaurus would have been able to walk on all fours or just its hind legs, as a biped, depending on what suited it.  Its front limbs were relatively the middle three fingers on each hand were fused together and tipped with a large hoof-like claw.  Its tail was long and extremely robust, and would have served as a counterbalance for the animal if it walked or ran on its hind legs.  The tail also could have served as an effective weapon to keep predators away or even knock them over if swung hard enough, if needed.  

References

Dodson, Peter (1975). "Taxonomic implications of relative growth in lambeosaurine dinosaurs". Systematic Zoology. 24 (1): 37–54.Simpson, D.P. (1979). Cassell's Latin Dictionary (5th ed.). London: Cassell Ltd. p. 883. 

Evans, David C.; Reisz, Robert R. (2007). "Anatomy and relationships of Lambeosaurus magnicristatus, a crested hadrosaurid dinosaur (Ornithischia) from the Dinosaur Park Formation, Alberta". Journal of Vertebrate Paleontology. 27 (2): 373–393.

Horner, John R.; Weishampel, David B.; Forster, Catherine A. (2004). "Hadrosauridae". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria(2nd ed.). Berkeley: University of California Press. pp. 438–463.