Lythronax: Tyrannosaur troubles

From left to right: Teratophoneus, Lythronax, & Bistahieversor

From left to right: Teratophoneus, Lythronax, & Bistahieversor

This was an exciting week for tyrannosaur fans, as a new tyrannosaurine was named (Lythronax) and new fossils of Teratophoneus were revealed.  Eagle-eyed visitors to the Skeletal Drawing theropod gallery probably realize that they've seen two of these skeletals before, but it may not be the two you would expect. Read on for a good lesson in always labeling your files clearly.

Teratophoneus was done as part of the revamp of the UMNH dinosaur halls. It incorporated the data published this week, but since Teratophoneus had already been described I was able to show off the skeletal while remaining mum on which parts were new and which were inference. The Lythronax skeletal was also produced a couple of years ago, but I was a bit less lucky on Lythronax, and it is here that the story takes an entertaining turn.

Given Lythronax's close relationship to Bistahieversor I quite reasonably used parts from it to help constrain the poorly-known postcrania. Better yet, because the two shared so much of the restored postcrania I went ahead and created a skeletal of Bistahieversor at the same time. In fact there was a time when I assumed they would end up as the same animal (or at least the same genus). And that's what got me in trouble.

Tired of labeling my two year old Lythronax skeletal "Wahweap tyrannosaurine" (and not yet knowing it would get a new name) I labeled a copy of it Bistahieversor perhaps a year ago. And then this June I revamped my website. Unfortunately while batch-converting skeletals to get them ready for the skeletal galleries I grabbed the wrong "Bistahieversor" skeletal, thus prematurely showing off the Lythronax skeletal under the wrong name.

I realized the mistake in late summer and considered swapping in the correct skeletal, but some of you are really observant and I was concerned someone would catch the switch. Instead I just stayed pat until this week, when Lythronax was named. So now the skeletals are properly labeled, but it's not actually Lythronax that you haven't seen before, but rather my skeletal of Bistahieversor, which can now regain it's proper place.


Loewen, M. A.; Irmis, R. B.; Sertich, J. J. W.; Currie, P. J.; Sampson, S. D. (2013). "Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans". PLoS ONE 8 (11): e79420.