From: Dinogeorge@aol.com
Reply-To: Dinogeorge@aol.com
To: dinosaur@usc.edu
Subject: Re: (no subject)
Date: Mon, 12 Mar 2001 12:45:27 EST
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.