[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Dinosaurs to birds
On Thu, 21 Jan 1999 Dinogeorge@aol.com wrote:
> 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).
Then how do you explain the disappearance of enantiornithines? More bad
luck?