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Re: Waiting for a giant bird and dino physiology revisted




On Sat, 12 May 2001, David Marjanovic wrote:

> This should still be enough for *T. rex* sizes. _All_ theropods, not just
> birds, have bent knees and are bipedal. Of course, there was no selective
> pressure for any neornithine to get that big.

Maybe a better way to say this is that were _stronger_ selection pressures
keeping birds small.  For example, in the absence of predation in New
Zealand, selection pressures were plenty strong enough--what selection
pressures for large size could there be on NZ that were absent everywhere
else (most places, anyway).  None, I think!