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Re: paleontolgist, dinosaur



From: Jeff Poling <jpoling@dinosauria.com>
 >  This is the first time I've seen this hypothesis.  I doubt it's true.
 > The first known flying bird is mid Jurassic, some 75 million years before
 > the K/T event.  Recent fossil finds show that birds were widespread and
 > diverse by the early Cretaceous at the latest ... yet pterosaurs survived
 > right up to the big figurative boom.

True, they survived, but apparently at *greatly* reduced diversity.
Only about three families of large "Pteranodon"-like forms are known
from the entire Late Cretaceous.  This is compared to the enormous
variety of smaller pterodactyloid and rhamphorhyncoid pterosaurs
known from the Late Jurassic.  And I know of only one or two families
from the Maastrichtian (the one containing Quetzalcoatlus, and perhaps
the one containing "Titanopteryx", if that is distinct). Indeed I
only know of a small handful of *genera* in the Maastrichtian.

Thus, the idea is that by the middle of the Cretaceous most of the
*smaller* flying niches were occupied by birds. Thus only a a few
individual extinctions were needed to finish off the pterosaurs,
unlike the still diverse dinosaurs.

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.