[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Tyrannosaurus and...



Christopher Pearsoll wrote:

I have a question concerning Tyrannosaurus, and while I'm sure I'm >beating the second or third largest dead horse on the DML, (BAND or >ABSURD anyone?) I would like some clarification. Are there one, two or >three species of Tyrannosaurus, or are T. bataar and T. luanchensis
(and any others I might have missed) suppposed to be distinct genera as >well as species. I have seen this arguement rage back and forth and I >was curious as to the current whereabouts of the most recent concensus >on this matter. Thanks in advance for any answers received on this >issue.

George recently posted a couple of messages about just this subject (and all things tyrannosaur):


http://www.cmnh.org/fun/dinosaur-archive/2001Jan/msg00670.html

and

http://www.cmnh.org/fun/dinosaur-archive/2001Jan/msg00671.html

To summarize the parts pertaining to your questions:
Most researches currently consider Tarbosaurus and Tyrannosaurus to be separate genera.
Tyrannosaurus has only one species, that being T. rex which includes ALL late Maastrichtian North American tyrannosaurids (so far described - this included Nanotyrannus lancensis, Dinotyrannus megagracilis, Stygivenator molnari, and all late Maastrichtian teeth referred to Aublysodon).
Tarbosaurus most likely includes two species: T. bataar, known definately from the early Maastrichtian of Mongolia, is the larger (about 14 meters), more massive, and less abundant of the two (this species most likely includes Gorgosaurus lancinator); and T. efremovi, known from the late Campanian-early Maastrichtian, is smaller (about 10-12 meters) and much better represented (this species probably also includes Maleevosaurus novojilovi).
T. luanchuanensis is based on the holotype tooth (Dong, 1979) and four teeth referred by Dong (1987) from the late Campanian Quiba Formation of Henan Province China, and is considered a nomen dubium. It is most definately referrable to Tarbosaurus, and George (I believe the reference is Olshevsky & Ford, 1995 - correct me if I'm wrong) tentatively referred it to T. bataar (as Jenghizkhan bataar). I consider it as Tarbosaurus species indeterminate, but it may indeed belong to T. bataar based on its large size. Other nomina dubia that are I consider Tarbosaurus sp. indet. are Albertosaurus periculosis, and possibly the nomen nudum T. turpanensis - and I probably missed some.


Sorry, that "summary" was a lot longer than I intended! :-]

Bronson J. Barton
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com
--- Begin Message ---
I have a question concerning Tyrannosaurus, and while I'm sure I'm beating the second or third largest dead horse on the DML, (BAND or ABSURD anyone?) I would like some clarification.  Are there one, two or three species of Tyrannosaurus, or are T. bataar and T. luanchensis (and any others I might have missed) suppposed to be distinct genera as well as species.  I have seen this arguement rage back and forth and I was curious as to the current whereabouts of the most recent concensus on this matter.  Thanks in advance for any answers received on this issue.


Get your FREE download of MSN Explorer at http://explorer.msn.com


--- End Message ---