Re: Tarbosaurus?

[Dinogeorge@aol.com]

In a message dated 7/20/00 11:50:25 AM EST, tholtz@geol.umd.edu writes:

<< So, given this, there are two choices: call it _Tyrannosaurus bataar_ or
 call it _Tarbosaurus bataar_.  Should you have evidence that the Mongolian
 form is more closely related to _T. rex_ than to any other named
 tyrannosaurid, then you can use the first of these names to convey that.
 However, there is nothing illegitimate about using the name _Tarbosaurus_,
 and for that matter should you consider _Tarbosaurus_ to be more distantly
 related to _T. rex_ than some other named tyrannosaurids, then you most
 certainly SHOULDN'T call it _Tyrannosaurus bataar_! >>

There are other possibilities: Namely, Tarbosaurus efremovi and Tyrannosaurus 
bataar could well belong in different genera, >neither< of which is 
Tyrannosaurus. Then the generic name Jenghizkhan is available for the species 
Tyrannosaurus bataar. Tarbosaurus efremovi specimens outnumber Jenghizkhan 
bataar specimens by about 15 to 3. If T. efremovi is a juvenile or subadult 
of a larger species, why are most of the specimens of this species juveniles 
and subadults, throughout all of the Mongolian Upper Cretaceous? How many 
juvenile or subadult Tyrannosaurus rex specimens are there in North America? 
How about Gorgosaurus, Albertosaurus, and Daspletosaurus?