Tyrannosaurus rex is without a doubt the most famous dinosaur in the world, and one of the lasting questions people have about this amazing dinosaur is what it was like as a teenager before it was full grown. A paper I co-authored with Bruce Rothschild, a former research affiliate with the University of Kansas Biodiversity Institute, now published online in the journal Cretaceous Research addresses this interesting question.
A nearly complete dinosaur skeleton labeled as BMR P2002.4.1, but more affectionately referred to as 'Jane' in honor of the woman who discovered it, has been the center of a decades long dispute over the validity of a dinosaur called Nanotyrannus lancensis. Nanotyrannus was named by a team led by the famous paleontologist Bob Bakker as a 'pygmy tyrannosaur' from the Late Cretaceous of Montana1. Not all dinosaur paleontologists are convinced of this assessment, and many prominent studies have asserted that Nanotyrannus—specifically 'Jane', the original holotype fossil skull at the Cleveland Museum of Natural History, and a handful of other isolated remains—are instead remanants of immature T. rex. In fact, if you visit wikipedia's page for Tyrannosaurus rex, you will find a proudly displayed image of 'Jane' from the Burpee Museum of Natural History. While paleontologists in this debate have focused on the number of teeth in the jaws2, the overall shape and proportion of the skull3, and whether the texture of the bone is more similar to that of adults of immature individuals4, we observed an isolated character on the skeleton of 'Jane' that shed some additional insight on this debate.
A portion of 'Jane's' lower jaw (called the dentary bone) is marked by a deep groove containing numerous small openings. Bruce Rothschild, who is an expert on ancient diseases and has looked at many jaws from theropod dinosaurs, was unaccustomed to seeing such a feature in a tyrannosaur, and thought this groove was possibly a sign of some disease. It turns out that the other specimens of the embattled genus Nanotyrannus also shared this feature, so it likely wasn't evidence of a disease. After examining additional dinosaur fossils, we found out that, in fact, this groove is found on nearly all theropod dinosaurs outside of the tyrannosauroid group (the group more closely related to T. rex than other meat-eaters like Allosaurus, Spinosaurus, and Coelophysis). Among tyrannosaurs, however, we found an opposite trend: only 7 of 18 tyrannosaurs had this feature, and half of those occurences were found in the group of the earliest tyrannosaurs. We further investigated this question by examining known T. rex material, ranging in age from "baby" all the way to full grown adult, and found that none of these fossils showed the groove we found on 'Jane'!
So what does this mean? It could be that 'Jane' and all the other fossils we call Nanotyrannus really are juvenile T. rex, and they are undergoing a really dramatic bodily transformation during their growth into adults (puberty sure is rough!), but this is unlikely given that none of the undisputed T. rex fossils we investigated have this feature. This groove is a passageway for nerves and blood vessels to move through the bones of the skull, and short of saying that the nerves and veins of the head dramatically changed their placement as the animal grew, if a baby has no groove, a sub-adult has no groove, and a full-grown adult has no groove, one would logically not expect a juvenile to have a groove either. To us (and some of the other scientists arguing in favor of Nanotyrannus), this is evidence that Nanotyrannus is a different dinosaur from T. rex, and they likely preferred different environments and prey even though they lived at the same time.
What does this mean about how Nanotyrannus fits in to the dinosaur family tree? Even though Nanotyrannus has been variously proposed to be a young T. rex or a closely related species, our phylogenetic analysis actually places Nanotyrannus as a close relative of the albertosaurine tyrannosaurs (moderate-sized theropods that lived in what is now Canada). We obtained this result because they are the only group of advanced tyrannosaurs to possesses the groove we studied. This result was interesting, however, because Charles Gilmore, the paleontologist that described the original Nanotyrannus on display at the Cleveland Museum5, thought it was an example of a new species of Gorgosaurus, one of the types of albertosaurines. History seems to have come full circle.
So now what? Well to the fan club of Nanotyrannus, we have some additional evidence that this was in fact a separate dinosaur species. And for now, the hunt is back on for a complete fossil that shows us what the mighty T. rex was like as a teenage terror.
1. Bakker et al., 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the Latest Cretaceous of Montana. Hunteria 1:1-28.
2. Larson, P. 2013. The case for Nanotyrannus. Pp. 14-53 in Parish et al. (eds.), Tyrannosaur Paleobiology. Indiana University Press.
3. Carr, T. 1999. Craniofacial anatomy in Tyrannosauridae (Dinosauria, Coelurosauria). Journal of Vertebrate Paleontology 19:497-520.
4. Currie, P. 2003. Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada. Acta Palaeontologica Polonica 48:191-226.
5. Gilmore, C. 1946. A new carnivorous dinosaur from the Lance Formation of Montana. Smithsonian Miscellaneous Collections 106:1-19.
This past August, I returned to the University of Kansas – and Natural History Museum and Biodiversity Institute – becoming the new Collections Manager in the Division of Herpetology. August couldn’t have made for a better homecoming, as KU was celebrating 100 years of herpetological research by hosting the annual SSAR (Society for the Study of Amphibians and Reptiles) meeting. The meeting offered a perfect opportunity to connect with so many whom have helped build this division into one of the greatest centers for herpetological research in the country, if not the world.
Over these few first, short months I’ve received nothing but support from students and colleagues, making the transition from student to employed researcher nearly seamless. This support has afforded me the flexibility to take on the responsibilities associated with managing a collection of more than 340,000 herpetological natural history specimens, while simultaneously wrapping up dissertation work towards a Ph.D. in Evolutionary Biology.
With the aid of a stellar group of undergraduate volunteers, an incredible curatorial assistant, and a cohort of graduate students that are second to none, we’ve been able to close outstanding loans of material that are years and even decades past due. We’ve also accessioned and incorporated into our collections several thousand specimens of amphibians and reptiles from the Philippines, Kansas (US), and Madagascar. Over the next few months, we’ll be doing the same for recent collections from the Solomon Islands, Indonesia, Malaysia, and Cameroon. Additional projects on the horizon include continued digitization of specimen photographs, calls, and other ancillary data, and a complete inventory of our tissue and dry collections.
I’m very much looking forward building on the storied history of herpetology at the University of Kansas. From modernizing the use of the collection, to maintaining it’s availability for researchers in the international community, and even contributing to it directly through my own research endeavors, I hope to play an integral roll in the future of herpetology here at KU.
A fisherman in southwest China stumbled upon a 200-year-old Chinese giant salamander weighing over 100 pounds. The four-and-a-half foot long specimen greatly surpasses the average lifespan of the critically endangered species. Giant salamanders are thought to live 80 years in the wild. The salamander found in China has been transferred to a research facility for study.
An adult Japanese Giant Salamander(Andrias japonicas).
Species of the giant salamander are found in both China (Andrias davidianus) and Japan (Andrias japonicas). Oddly enough, the closest relative to these living fossils is the Hellbender (Cryptobranchus alleganiensis) found in eastern North America. The hellbender, on average, grows to half the size of the giant species. KU Herpetology Collections Manager Luke Welton says giant salamanders diverged from the hellbender 65 million years ago.
Despite the distance between their homes, all three species have similar habitats and lifestyles. Welton says the three species spend little time on land due to poorly developed lungs, and instead absorb most of their oxygen through folds of skin on their sides. As a result of this preference, all three prefer cold, fast-running streams and lakes. Salamanders often seek refuge beneath large submerged rocks and boulders.
Several specimens of the hellbender and both species of giant salamander are part of the KU Biodiversity Institute Herpetology Collections.
A KU Herpetology lab snaps a selfie before releasing a hellbender found in the Niangua river near Bennet Springs, Missouri.
This Thanksgiving, don’t think of the yearly tradition as just carving up a turkey. In reality, you’re dissecting your very own dinosaur.
KU Paleontologist David Burnham studies ancient raptors of all sizes. Studying these ancient relatives fills the gaps between raptors of the past and the turkeys we eat today. Upon studying this lineage, one can see that turkeys and raptors have much more in common than you may think, despite differences in how we traditionally picture a “bird.”
“The public’s perception of what a bird may be might not be the definition a scientist would use,” said Burnham.
The public largely defines birds by their feathers and flight capabilities. By comparison to their ancestors, not only do both prehistoric raptors and modern birds share feathers, but many living birds also either rarely or never use flight including ostriches, emus, cassowaries and turkeys.
“The loss of flight has evolved several times throughout that lineage,” said Burnham. “If we want to draw a line when theropod dinosaurs became strictly avian, well, we’re still refining that even today due to the enormous amount of new discoveries.”
What’s important to remember is that dinosaurs never fully became extinct. The ones that survived mass extinction merely changed. Birds such as turkeys and chickens share their lineage with theropods, or two-legged meat-eating dinosaurs. The skeletal structures of turkeys and extinct theropods such as Velociraptor, Bambiraptor and Microraptor retain several similarities in particular.
Here are some points to look for while dissecting your “dinosaur” this Thanksgiving:
- Wishbone - The furcula, or wishbone, is a major connection between the turkey and its ancient theropod ancestors. The furcula is made up of two formerly separate collarbones, fused together. This evolutionary change aided in flight capabilities of ancient raptors such as Microraptor, and continues to help modern birds, such as turkeys, reach liftoff.
- Wings - The turkey wing deserves careful inspection. The fleshed-over tip is where claws protruded from theropod arms such as those of Velociraptor, Bambiraptor, and even the massive Dakotaraptor. Imagine those on your dinner plate! As theropod dinosaurs evolved, their arms became longer and those claws were covered by flesh forming wings suitable for extended flight – an easily recognizable feature of avian species we see today.
- Thighs and drumsticks - These are often the most sought after pieces of the feast, and still quite similar to the legs of theropods. This leg structure allowed raptors to reach impressive ground speeds; Velociraptor is thought to have been able to run as fast as 40 miles per hour! The turkey on your table is no slowpoke either thanks to this ancient design, with a top running speed of 25 miles per hour.
While the turkey still possesses many remarkable features harkening back to its raptor relatives, there are some things we can be thankful were lost during evolution.
“Of course, turkeys don’t have teeth,” said Burnham, “and that’s probably a good thing.”
I'm currently in the Bahamas for a field trip with recent Glor Lab PhD graduate and current Harvard University postdoc Anthony Geneva. We started our trip with a few days of sampling on Eleuthera Island and are now on our way toward South Andros Island, where we'll spend a few days before proceeding to North Andros Island. We're primarily interested in sampling two widespread species of Anolis for a few projects about speciation and adaptation, but are also sampling herpetofaunal diversity more generally. The photograph above is of a Bahamian Racer (Cubophis vudii) that crawled into my camera bag.
The KU Biodiversity Institute and Natural History Museum seeks a Science and Public Programs Communications Intern
This student position assists the director of external affairs. The intern will work on a variety of projects spanning the outreach programs of the museum and the research programs of KU Biodiversity Institute scientists and students. Content may span written, audio and video formats, depending on the skills the intern brings to the position. Candidates with an interest in science writing are strongly encouraged to apply.
Specific tasks may include:
conducting interviews and developing features for biodiversity.ku.edu;
supporting our efforts in social media such as Facebook, Twitter and Instagram; and
assisting the director with communications to the public, media, and museum members.
Junior, senior or graduate student level standing;
Majoring in journalism, communications, biology or a related field;
Strong English writing and editing skills as demonstrated by coursework, samples, resume and cover letter;
Familiarity with social media platforms as indicated in application materials;
Experience with basic Office software skills (Word, Excel);
Available to work 10-15 hours per week during weekdays
Experience with writing about science or research;
Proficiency with Adobe programs (Photoshop, Illustrator, InDesign);
Experience with online content creation and/or video production.
Full details and application at employment.ku.edu.
Curator Emeritus Bill Duellman's book on the history of herpetology at the University of Kansas is now available. From the back cover "The University of Kansas has long been recognized as having one of the world's leading centers for research and education in herpetology. This book chronicles the people - faculty and student alike - who have contributed to maintaining and expanding KU's herpetology program and details their lives, education, research, and fieldwork. The book also describes how a true institutional program, one that transcends individuals, was created and sustained over such a long period through innovative planning and social development. The KU herpetological collections comprise one of the largest and most comprehensive museums of amphibians and reptiles in existence, now numbering in excess of 332,000 alcohol-preserved specimens, together with ancillary collections of osteological preparations, color images, frozen tissues, audio recordings, and the associated scientific literature. This book provides an insider's in depth review of the many successes as well as plans that went awry or even courted disaster. Altogether this book represents a substantial and critical chapter in the history of the discipline of herpetology."
Curator Emeritus Bill Duellman saw two books published in the Summer of 2015: Herpetology at Kansas: A Centennial History (published by SSAR) and Marsupial Frogs: Gastrotheca & Allied Genera (published by Johns Hopkins Press). Here, from it's back cover, is a bit more detail on the marsupial frogs book that is now available via Johns Hopkins Press: "This scientific masterpiece reveals many aspects of the lives of marsupial frogs and closely allied genera. Native to central and south America, these amphibians differ from other frogs in that they protect their eggs after oviposition by either adhering them to the female's back or placing them in a specialized dorsal pouch (thus the common name, marsupial frog). During mating, the male typically collects the eggs from the female with his feet - often one at a time and always out of water - fertilizes them, and then tucks them into the female's pouch or attaches them to her back. In some species these eggs hatch as tadpoles, but most emerge as minatures of the adults. Even among the tadpoles there is remarkable convergence, with some behaving in the typical manner (feeding and metamorphosing) and others not feeding until they metamorphose. In Marsupial Frogs, William E. Duellman's synthesis of all that is known about the unique family Hemiphractidae is largely based on decades of his own careful laboratory and field study. He reveals the diversity of the frog's exotic color patterns and geographic distribution. More than 200 photographs, illustrations, and maps accompany the detailed text. This exceptional reference should find its way into the libraries of serious herpetologists, tropical biologists, and developmental biologists."
We are pleased to announce that this year's Herpetology Quiz will offer a total of $1800 worth of SSAR publications as prizes! The herpetological quiz comprises of 50 questions based on broad herpetological topics. Each question is worth 1 point and a total of 50 possible points. KU Herpetology Graduate Students will offer two opportunities to take the quiz: Friday and Saturday evenings from 5-6pm in the Pine room on Level 6 of the Kansas Union. The format is a multiple choice and will include many questions based on images. The prize pool will be divided among competitors in three categories: undergraduates graduate students. Winners will be announced during the auction!
Kansas has a very rich herpetofauna, with about 100 native species of amphibians and reptiles. Live specimens of nearly every species will be on display this week for the SSAR meeting, with the exception of venomous snakes. The live animal exhibit will occur in Gathering Room 1 of the Oread Hotel on Thursday 4-8pm and Friday through Sunday 8:30am-6pm ad is open to the public. Species on exhibit will include: Western Narrow mouth Toad (Gastrophryne olivacea), Western Tiger Salamander (Ambystoma mavortium), Alligator Snapping Turtle (Macrochelys temminckii), Eastern Collared Lizard (Crotaphytus collaris), Texas Horned Lizard (Phrynosoma cornutum), Western Milksnake (Lampropeltis gentilis), and Grahamês Crayfish Snake (Regina grahami). This will be a unique opportunity to observe these animals upclose and be able to photograph them. Staff members can answer questions and assist with photography. SSAR started live displays at its meetings in 1968 as a conservation measure to offset collection of wild animals in the vicinity of meeting venues. Turning loose hundreds of eager herpetologists in one locale is bound to have negative effects on the local herpetofauna. Additionally, many species are highly seasonal or difficult to find, so having local herpetologists make a representative collection over the course of a year or more is ideal. We are most grateful to the membership of the Kansas Herpetological Society for making the herculean effort to bring all these animals together and for getting the necessary permits from the Kansas Department of Wildlife, Parks,and Tourism to do so. Many specimens come from the live collection of the Sternberg Museum of Natural History at Fort Hays State University. In particular, we wish to thank Dexter Mardis, Curtis Schmidt, Travis Taggart, and Chris Visser. The person in charge of the exhibit is Dan Fogell (email:firstname.lastname@example.org). Please contact him if you have any special needs, concerns, or questions.