Tyrannosaurus

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 05:06 PM 10/31/97 PST, you wrote:
>Hi!
>
>Tyrannosaurus is one of the best known carnivorous dinosaur. This genus
>encompasses five different species.

Maybe.  T. luanchuanensis is a non-diagnostic form.  There may be only two
species within Tyrannosaurus..

>Tyrannosaurus rex is from USA and 
>Canada. It was about thirteen meters long. Tyrannosaurus efremovi was from
>Mongolia. It was about eleven meters long. Tyrannosaurus bataar is a
>thirteen meters long predator from China and Mongolia.

Note that it is very difficult to tell if T. bataar is simply a fully grown
T. efremovi, or a different species.  The type specimen (skull and
fragmentary postcrania) of T. bataar lacks those parts of the anatomy which
would show whether it has the derived states found in T. rex or the derived
states found in T. efremovi.  Also, T. bataar is only known from Mongolia.

>Tyrannosaurus
>novojilovi was the smallest species with "only" six meters. It was from
>Mongolia.

And may be no more than a juvenile of T. bataar and/or T. efremovi.

>Tyrannosaurus luanchuanensis is from China. I think it was twelve
>or thirteen.

Just teeth.  Not a diagnostic taxon.

>Tyrannosaurus has long teeth, powerful jaws, a short neck,
>very short forelimbs with two fingered hands, long hindlinbs with birdlike
>feet, and a long tail. It was one of the largest of all carnivorous
>dinosaurs.
>

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661