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Re: (no subject)



In a message dated 3/12/01 11:49:20 AM EST, Tetanurae@aol.com writes:

<< Additionally, I think youre still not understanding the point I was trying 
 to make.  The very, very large range in Asia that psittacosaurs lived in, 
 as well as the probably very extensive temporal range that psittacosaurs 
 lived demonstrates that they didn't all live together and weren't competing 
 directly.  In fact, you'd be hard pressed to find two species of 
 Psittacosaurus 
 that even SAW each other alive, save for P. sinensis and P. youngi.  
 Insisting 
 that all the various species of Psittacosaurus must be lumped into one or 
two 
 is like insisting that all the various fossil equids in North America must 
be 
 lumped into one or two equid species because they lived in North America and 
 lived during the Cenozoic. >>

I strongly suspect that if the fossil record were more complete, we would see 
>at least< this kind of diversity for practically all the genera of smaller 
dinosaurs, and close to this kind of diversity for the genera of larger 
dinosaurs, too. The diversity of the very largest dinosaurs, however, would 
probably not be much greater than what we already know, since the sampling of 
the fossil record is heavily biased toward forms the leave large fossils.