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Re: My apologies, but... physiology revisited
Dogma in paleontology? These are wild accusations, Mickey!! ;)
Well, yes, but try to get a mammal paleontologist to give some
hard evidence of fur on or endothermy in Morganucodon or Oligokyphus.
Nobody goes nuts when they propose insulation and endothermy for these
animals. Yet until recently it was supposedly bad science to put feathers
on birds, or propose endothermy for dinosaurs. This doesn't excuse any
shoddy arguments, but the fingers shouldn't point one direction only.
And is one who studies dinosaurs being dogmatic when they refuse
to automatically accept Ruben et. al.'s arguments, but Jones is not
dogmatic when he refuses to take the word of an expert like Currie on the
subject of dinosaur feathers, who has examined the fossils in detail and
in person? Personally, I think both are being cautious. I happen to know
for a fact that the thing did have insulation, but I admit that some
caution would be necessary if I hadn't in fact seen some good hard
evidence. Everyone has an angle and a bias, I'm sure Currie has his own
prejudices on various subjects just like everyone else does, for all I
know one of those is a rabid need to find dinosaur feathers.
The fact is, insulation and RT do not appear in ectotherms as far
as we know. A certain minimum of insulation may be absolutely necessary to
endotherms (from size and fat if not from hair or feather) with any kind
of mammalian or avian-level physiology. RT is a good idea if >99% of
endotherms have it but obviously not necessary if pelicans don't. So if we
find a feathered animal without RT we should be justified in proposing it
as an endotherm.
Does the RT thing bother me? Yes. But not as much as ditching
everything we know about the dinosaurs global distribution, competition
with presumably endothermic mammals, protomammals and birds, their average
walking speeds, growth rates, average sizes, and skeletal, muscular,
respiratory, integumentary and circulatory systems, and the fact that all
living dinosaurs are endothermic, and their closest relatives, the
pterosaurs, in all likelyhood were as well.
I don't know the answer. But what Jones and Ruben argue flies in
the face of about a dozen arguments in favor of endothermy and fails to
explain these observations. Dinosaur endothermy doesn't fit all the data,
but it shows promise of eventually being able to fit it all in. If
eventually we develop a truly robust model of dinosaur endothermy, you can
be sure that the RT argument will be addressed on the way.
Notice also that Jones argues that pterosaurs were cold blooded
(56th annual JVP abstracts of papers), because pterosaurs lacked
avian-style lungs, apparently ignoring the fact that pterosaurs had hollow
bones and openings allowing them to connect to the lungs as in modern
birds (Wellnhofer's book). I missed that one, though, so maybe he had
something to say beyond what appears on the surface to be complete
ignorance of the evidence in this case.