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basking and thermoregulatory physiology (was Re: Feduccia's errors)



Greg Paul wrote:

> There is no evidence that ectotherms dependent upon large amounts of
> environmental heating can afford to be insulated.

I'm *not* going to get dragged back into this, but from my perspective
it seems people focus way too much on extreme positions (I think it
was two years ago that I was making the same arguments over on
VRTPaleo, and in that case I was arguing with someone who seemed
overly confident that dinosaurs were ectotherms...).  Endothermy (as
practiced by modern mammals and birds) results from suites of
characters.  It's not just one thing, so you can't a) give one of
those characteristics to a modern ectotherm to demonstrate the
impossibility of that trait's existence without the rest of the suite
and b) conversely you can't conclude that because an animal had one
character from the suite that it had them all (at least not to the
degree that modern endotherms have them).

Note that this is different from the RT argument.  In that case, the
argument is that no animal can have the chronically high metabolic
rates (resulting from a suite of characters) of modern endotherms
without some mechanism for retaining respiratory water.  IMHO, the
only thing left to argue on this point is whether or not there is any
evidence that dinosaurs had such a mechanism.

Finally, I confess I haven't done all of my homework with respect to
invertebrates (there are a couple of books by Bernd Heinrich that I
think ought to be widely read by participants of these discussions).
I suspect some fuzzy little bugs may prove Greg's contention wrong.
If anybody gets (or has gotten) to these books first, by all means
enlighten us!

--
Mickey Rowe     (mrowe@indiana.edu)