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RE: Function Talks at Ostrom Symposium

        -----Original Message-----
        From:   EctoDino@aol.com [SMTP:EctoDino@aol.com]
        Sent:   Friday, February 19, 1999 11:16 PM
        To:     dinosaur@usc.edu
        Subject:        Re: Function Talks at Ostrom Symposium

        Thomas R. Holtz, Jr said:
        > Others asked why would it be that a hypothetical
        >  diaphragm breathing would be incapable of being the ancestor of
         So did they let Ruben answer? It seems he answered that question in
        11/14/97 Science, p. 1269, where he says that a "diaphragm
        ancestor would have necessated selection for a diaphragmatic hernia
in taxa
        transitional between theropods and birds. Such a debilitating
condition would
        have immediately compromised the entire pulmonary ventilatory
apparatus and
        seems unlikely to have been of any selective advantage."
        So is it answered in advance?



           How certain is it that dinosaurs WERE diaphragm breathers?  And
why would the transition
        forms (IF dinosaurs were diaphragm breathers) be selected for a
diaphragmatic hernia?