Re: Have the tyrannosaurs imploded yet?

[Nick Pharris <npharris@umich.edu>]

Quoting Mickey Mortimer <Mickey_Mortimer111@msn.com>:

> Check-
> Carr, 1999. Craniofacial ontogeny in Tyrannosauridae (Dinosauria,
> Coelurosauria). Journal of Vertebrate Paleontology, 19: 497-520.
> Holtz, 2001. The phylogeny and taxonomy of the Tyrannosauridae. In Mesozoic
> vertebrate life. Edited by Tanke and Carpenter. Indiana University Press,
> Bloomington and Indianapolis, Ind., pp. 64-83.
> Currie, 2003. Allometric growth in tyrannosaurids (Dinosauria: Theropoda)
> from the Upper Cretaceous of North America and Asia. CJES 40, 651-665.
> Currie, P.J., Hurum, J.H., and Sabath, K. 2003. Skull structure and
> evolution in tyrannosaurid dinosaurs. Acta Palaeontologica Polonica 48 (2):
> 227-234.
> Hurum and Sabath, 2003. Giant theropod dinosaurs from Asia and North
> America: Skulls of Tarbosaurus bataar and Tyrannosaurus rex compared. Acta
> Palaeontologica Polonica 48 (2): 161-190.

In other words (correct me if I'm wrong):

_Tyrannosaurus_, _Tarbosaurus_, _Daspletosaurus_, _Albertosaurus_,
_Gorgosaurus_, _Alioramus_, and _Alectrosaurus_ are probably valid (possibly
also _Nanotyrannus_, based mostly on its unexpectedly high tooth count), while
_Jenghizkhan_, _Dinotyrannus_, _Aublysodon_, _Stygivenator_, _Shanshanosaurus_,
and _Maleevosaurus_ all likely represent ontogenetic stages of either
_Tyrannosaurus_ or _Tarbosaurus_.

By "valid", of course, I mean that the genus in question contains at least one
valid species.  Whether some of these genera should be consolidated depends
partly on the topology of the tyrannosaur family tree and partly on personal
taste.

Several new species await publication.

Nick Pharris
Department of Linguistics
University of Michigan