This skull look superb, but in reality it’s a lot of very good sculpting work bolted onto a case of a partial maxilla and anterior dentary. That’s as much as I could see and it looks like that’s all there is of the cranium. I know the original forms part of the display at the revised LACM exhibit in Los Angeles and I think this is the specimen called ‘Jane’, but not much more than that. Although much of this is reconstructed it’s not only well done but looks about right for such a young juvenile (it’s a fraction of the size of an adult skull) and has been put together with large orbits and a proportionally long and narrow skull – basically an extension / exaggeration of the changes we can already see from non-adult (if still large) tyrannosasurs.
Dave Hone's Archosaur Musings 
Hi Dave;
I think the anterior bit is from a specimen known as the “Jordan Theropod” rather than “jane”. I think Jane is a good deal bigger if I recall.
That is indeed correct: this is the Jordan Theropod (the one-time “Stygivenator molnari“.) Anterior end of the snout (including dentary), part of the skull roof, rear end of a mandible are what is known.
Jane is indeed bigger and older: “Stygi” is a 2 year old, “Jane” about 11.
Thanks for that guys. Hard to tell when the material is unlabelled!
What’s that little crest like thing on the back of the skull? I never knew they had that. Almost looks like a Cryolophosaurus crest.
Wait, I just noticed the odd bone sticking out of the back of the Tarbosaurus skull in the Dr. Holtz photo. Is that the same bone? What is that bone? I never noticed it till today.
I believe that’s the supraoccipital crest, where the neck muscles attach to the skull. It’s present in adults as well, but I’m thinking the museum might have maade it too big here.
Its an anchor point for powerful dorsal neck muscles, this is in pretty much all therapods but its very pronounced in some tyrannosaurs I believe.