Re: Proof at last? (hot-blooded T. rex)

["John V Jackson" <jjackson@interalpha.co.uk>]

-----Original Message--From: Phillip Bigelow <bh162@scn.org>Date: 30 March
1998 09:23
>
>Barrick, R.E., and W.J. Showers. 1994. Thermophysiology of
>    Tyrannosaurus rex: evidence from oxygen isotopes.
>    Science, volume 265:222-224.
>
>
snip
>
>>throughout the animal's body.  if the oxygen molecules are
>>equally distributed, than that means that the animal had the
>>same body tempiture everywhere in it's body therefore the
>>animal is warm-blooded.
>>--

. . . But warm-blooded animals don't have the same body temperature all
over.  (cf chocolate tipped siamese cats, whose dark extremities have been
shown to be due to temperature-sensitive pigmentation).   They generate heat
differentially from different organs (albeit transported by blood), and lose
it through the skin and lungs, thus maintaining various gradients.  I'd have
thought a
cold-blooded animal, more in equilibrium with it's environment, would be
more likely to have an equally distributed body temperature.

JJ