One of the more fascinating specimens in last year’s visit to the Museum of the Rockies was also one of the more diminutive. MOR 6625, also known as “Chomper rex”, is the smallest Tyrannosaurus rex found to date. It is known from, among other things, some fragmentary elements of the tiny skull. The high-tech road he took from there to the reconstructed skull displayed at the musuem is a story unto itself.
“Chomper” is just that - some chompers, if you will. More to the point, the skull reconstruction is based around some fragmentary lower jaw bones and a whole lot of digital work. The majority of the computer modeling involved taking known research and applying it to the model of BMRP 2002.4.1, better known as “Jane”, a younger T.rex specimen. By digitally “De-growing” Jane’s skull and applying information from their study of a similarly aged Tarbosaurus, researchers from the Witmer Lab at Ohio University created a composite model of what evidence suggests “Chomper’s” skull should look like.
To date, MOR 6625 is the smallest Tyrannosaurus rex specimen to be studied. An awful lot of what is presented here is admittedly a highly educated fill-in-the-blanks. That being said, Chomper represents a pretty enticing and interesting look at the intersection between old school and high tech. And given its position in the debate over the existence of Nanotyrannus, it’s not without some controversy. Plenty has been dedicated to that on this and other pages, so I won’t rekindle the debate here. But the research conducted by Witmer is of great interest to me, mainly because its a first look at a relatively early version of our namesake dinosaur.
Last year, researchers at Kansas University announced that they’d unearthed a baby tyrannosaur of similar age to Chomper. Further analysis is forthcoming. A few months before that announcement, I was fortunate enough to be invited to take a brief look at the fossil while it was being prepared. And while I wasn’t allowed to take any photos, it still was enough to whet my appetite. I am looking forward to seeing a lot more as this and other specimens are studied, and as more evidence is uncovered in what is now a gaping hole in the knowledge of one of our favorite dinosaurs. Witmer Lab’s work is commendable, and extremely interesting. It will be interesting to see how well “Chomper” holds up to what is revealed in the future.