[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Dinosaurs to birds



In a message dated 1/21/99 6:36:24 PM EST, Dwight.Stewart@VLSI.com writes:

<< Or (somewhat alternately): birds were sufficiently derived (in some way) to
 survive the KT extinction.  This is whether a bolide was the cause or just a
 contributor.  Some evolutionary adaptation that was present in Cretaceous
 birds, but not present in Cretaceous non-avian dinosaurs gave birds an edge
 (in this case). >>

Could also have been sheer luck. We have no good handle on bird diversity
during the Cretaceous, but if it was (as I think) quite high, then most of the
birds were killed off, too, and the post-Cretaceous bird radiation would have
stemmed from just a few (say 40-50) survivor lineages (out of, say, 500-1000).