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Re: CROCODYLOMORPH ENDOTHERMY
In a message dated 96-01-26 20:34:08 EST, pharrinj@PLU.edu (Nicholas J.
>> histology might make me sit up and take notice, but even that is
>> questionable. We have a hard enough time convincing anyone of dinosaurian
>> endothermy via bone histology, let alone of thecodontian endothermy, where
>> the deck is really stacked against it.
>Oh, really? Excuse me, but I'm not so sure.
I repeat: the only evidence at present that would unquestionably nail down
dinosaurian endothermy would be to take a time machine back to the Mesozoic,
take the dinosaurs' temperature on a number of occasions, and see whether you
obtain more or less the same figure.
This doesn't mean I _don't believe_ that dinosaurs were endotherms; it's just
much more a matter of faith than of science. Dinosaur endothermy is a simple,
unifying explanation for a lot of otherwise disconnected observations about
dinosaurs, such as bone histology, predator-prey ratios, erect stance,
footprints indicating a high level of activity, suppression of coeval
mammals, and phyletic proximity to birds. That's why I think dinosaurs were
endothermic to some degree or other. But many of these observations do not
extend back to thecodontians, so thecodontian endothermy is correspondingly
much more problematic. We don't need thecodontian endothermy to have
dinosaurian endothermy, for example.