Tanycolagreus (Stokesosaurus?) Skeleton

This is a Tanycolagreus topwilsoni, named by Ken Carpenter and collegues in 2005. The specimen was collected from Como Bluff, Wyoming, in the same quarry that Coelurus and Ornitholestes were collected from more than a century earlier. The hand is very similar to that of Yutyrannus and Dilong, in having a reduced digit 3 (pinkie) and some other features suggest that Tanycolagreus might be a basal tyrannosauroid.

As with all my new skeletal illustrations, I started by directly tracing the outlines of the individual bones to avoid as much distortion and artist-induced bias as possible. Then I reassembled them, bone by bone into the finished illustration. Ribs and gastralia were not illustrated for some reason in the description, and the number of caudal vertebrae illustrated is different than what was reported in the text, making the description of this animal surprisingly incomplete and poorly written. But I've done what I can with what was illustrated and described. I'll check out the actual specimens and casts next time I'm in Utah and make changes as necessary.

In the lower illustration, I've scaled up the ilium (hip bone) of Stokesosaurus to fit the preserved parts of Tanycolagreus. Why? Stokesosaurus is known from the Morrison Formation of Utah and was represented by an ilium and a premaxilla...UNTIL Ken Carpenter recognized that the premaxilla was identical to that of Tanycolagreuswhich doesn't have an ilium that can be compared. SO...does this mean that they are actually the same animal? OR is the ilium the only part of Stokesosaurus that is known and it was simply associated with a premxilla of Tanycolagreus? Nobody knows, so I drew Tanycolagreus as preserved (upper skeleton) and also with the ilium of Stokesosaurus (lower skeleton) just to cover all my bases.