Re: Lumpers and Splitters

[Adam Yates <zooamy@zoo.latrobe.edu.au>]

On Sun, 29 Oct 1995 RaptorRKC@aol.com wrote:

>  Why, suddenly, are some species of Aublysodon placed into
> a new genus, Sinraptor?.

Like the taxonomy of all other groups of organisms,that of dinosaurs is 
plagued by poor descriptions and names based on poor, non-diagnostic 
material. Most of this happened early on in the feild but the practice 
seems to continue. In this case Aublysodon mirandus was based on teeth. 
Although the unserrated D - shaped premaxillary teeth seem to be 
distinctive and obviously belong to primitive tyrrannosaurs it is far 
from certain how many species of these "Aublysodontines" exist. Indeed 
when the group is better understood it will be next to impossible to 
decide which one the holotype teeth belong to.This makes 
Aublysodon mirandus a nomina dubium (a dubious name that cannot applied 
to any other fossil other than the holotype)  Therefore G.O. erected the 
name Stygvenator (not Sinraptor) for the species "A." molnaris which is 
based on diagnostic material
(the Jordan Theropod - a snout of one of these "aublysodontines").    
Sinraptor is a newly described genus of large theropod from China, it is 
a close relative of Yangchuanosaurus. 

Adam Yates