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Re: Testing competitive exclusion in birds, bats and pterosaurs




----- Original Message ----- From: "Guy Leahy" <xrciseguy@sbcglobal.net>
To: <dinosaur@usc.edu>
Sent: Monday, May 07, 2007 1:53 PM
Subject: Testing competitive exclusion in birds, bats and pterosaurs



Neither birds nor
bats entered pterosaur morphospace across the
Cretaceous-Paleogene (Tertiary) extinction. Bats plot
in a separate area from birds, and have a
significantly smaller morphological range than either
birds or pterosaurs. On the basis of these results,
competitive exclusion among the three groups is not
supported.

Birds developed the specializations for marine soaring flight within 5 million years of the demise of pterosaurs (different requirements from terrestrial soaring). I think a speculative case could be made that pterosaurs may have been excluding birds from this niche. Note also that there is still no consensus that all or any pterosaurs had a wing-hindlimb connection. A universal wing-hindlimb connection in all species implies that pterosaurs were specialized for terrestrial soaring. Unusual in animals that seem to have been mostly fish eaters.
JimC