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Re: responses to pterosaur discussions

From: Ronald Orenstein (Wednesday, February 07, 2001 6:26 PM):
>But would you go into a study assuming that the physiological aspects of
respiration, which you cannot measure in pterosaurs (or in Mesozoic birds,
for that matter), were so much alike in birds and pterosaurs that a
difference in physical respiratory structure would translate directly into a
difference in respiratory efficiency?<

Don't forget what started all this. If memory serves, we wanted to account
for extinction of pterosaurs but not birds at or near the end of the
Cretaceous. Respiratory efficiency might do it. But then we have to make a
small assumption about respiratory systems, and maybe yet another about some
aspect of physiology. We lack evidence for both, yet both must be true as a
predicate condition for our "educated guess" to be correct. Then we hear
that the proposed explanation can only be true if yet something else is,
that we equally lack evidence for. Not only that, but maybe the atmosphere
had to be different. All this to account for birds outlasting pterosaurs.
No, this is not really an educated guess. It was Samuel Clemens who once
commented on science being a wonderful thing--you get such a great return of
conjecture from such a trifling investment of fact. (Sorry, I don't remember
his exact words.)