Re: Prosauropods

[Brent Jones <brentasaurus23@yahoo.com>]

--- Dinogeorge@aol.com wrote:
> In a message dated 8/2/02 5:36:04 AM Pacific
> Daylight Time, 
> s.aegyptiacus@free.fr writes:
> 
> << Funny, I was thinking that prosauropods could be
> basal dinosaurs, more
>  related to theropods than to sauropods, kind of
> early plant-eating or
>  omnivorous theropods >>
> 
> Not exactly a new idea--prosauropods were classified
> as basal theropods for 
> much of the 20th century, until it was shown that
> carnivore teeth associated 
> with many prosauropod postcranial remains were shed
> by predators/scavengers 
> and did not belong to prosauropods.

Does that rule out the possibility that prosauropods
could have been basal theropods? Looking at the new
discoveries (_Eoraptor_ and _Herrerrasaurus_), it
looks like the prosauropod line would have risen out
of a meat-eating bipedal archosaur, but what if that
isn't the whole story? Could dinosaurs have evolved
from small, omnivorous archosaurs that eventually gave
rise to the prosauropods, from shich the rest of the
dinosaurs evolved? Could there be some fossil out
there, undiscovered, that puts first dinosaur back a
little bit further?

As an aside of the whole "which came first..."
question, what is the latest thinking on the
ornithiscians? Did they evolve as plant eaters first,
then evolve the different hip structure to help digest
the tough plants?

Brent : )


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