Re: Fw: late night thoughts: misunderstand what?

[Tim Williams <twilliams_alpha@hotmail.com>]

Don Ohmes wrote:

> Our perspective on evolution is evidently very different. I don't think 
> that the end theropod being the biggest, and the end sauropod being the 
> most armored, and quite large, does anything to falsify the notion of a 
> prey/predator size race.

As David said, the largest titanosaurs tend not to be armoured.  If 
anything, the opposite is true.  For example, saltasaurids (one of the 
smallest sauropod lineages) have body armour.

> That T.rex evolved separately from the allosaurids seems indicative to me 
> that the evolutionary sub-strate was conducive to creating mega-predators. 
> Why would I conclude that sauropods weren't a part of that? While I can't 
> be certain they were, it seems to attain best 'guess status'.

Because Late Cretaceous sauropods from North America were not so "mega".  On 
the other hand, several ornithichian lineages do include exceptionally large 
taxa at the end of the Cretaceous in North America: Ceratopsia, Ornithopoda 
(as hadrosaurs), and Ankylosauria.

David M. already provided a terrific summary of why Cope's Rule appears not 
to apply to Sauropoda throughout the Mesozoic, so I won't elaborate on that 
point.

Cheers

Tim

_________________________________________________________________
Get a preview of Live Earth, the hottest event this summer - only on MSN 
http://liveearth.msn.com?source=msntaglineliveearthhm