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Re: Theories on the extinction of dinosaurs



>>
I can tell people are mystified by all those cute little flying birdies who
somehow made it past K/T. But it would be a good exercise to catalog the
number of living genera that exist in far-flung polar environments, and which
spend at least some of their time in burrows and caves. You might be
surprised. A cretaceous neornithine radiation might even have made it through
a heat-blast, given a similarly broad range of genera living under the dirt.

I don't doubt that there was a dust cloud and cooling, and that these may
have added a predominantly insectivore/endotherm character to the ultimate
survivors, but that may only have served to winnow down those who first
survived the blast.

At some point after blast-dust, you get to just about the right mix of
survivors. All due, then, to the impact.<<

I don't like the burrowing, hypothesis (although the air-breathing thing makes
perfect sence).  It depends on a behavior that only a few species would have.
Modern-day diversity is (I think) much more than that theory accounts for.  What
about crocodiles?

Dan