Re: Waimanu & avian evolution (comments)

[dinoboygraphics@aol.com]

Michael wrote:  "I find it interesting that smaller pterosaurs declined 
as birds diversified, but that soaring birds don't seem to have 
developed till after the pterosaurs were out of the way. At the end, 
they each seem to have been successfully filling different niches.",
which was consistent with his early statement: "I tend to think it 
likely that if the bolide hadn't come along, the big pterosaurs would 
have remained with us till man came along to do the bolide's work."

I certainly wouldn't split hairs with the specifics of the timing, but 
bollide aside, it appears to me that in the long term pterosaurs were 
already doomed by the K/T.  Arguements that pterosaurs made superior 
large soaring birds may well be correct, but the niches that birds had 
already out-competed them for were far more numerous.  At that point 
there was no more (or at least very few) small-bodied forms from which 
new linneages of giant pterosaurs could evolve from, so if a 
less-populous larger-bodied pterosaur clade went extinct, it would be 
statistically more likely to be replaced by an avian linneage, even if 
the replacement was competitively "inferior" in some manner.

Whether they would have kicked out in the Miocene, or the last ones 
would have hung on to be eliminated by deforestation (after posing with 
Civil War soldiers...) is anyones guess.

Scott Hartman
Science Director
Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(800) 455-3466 ext. 230
Cell: (307) 921-8333

www.skeletaldrawing.com