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Re: Extinction scenarios
> Regarding survival of non-burrowing mammals in Montana: Did they survive
> in Montana or Asia or Newfoundland? Any small population could have spread
> out to reclaim a devastated world in a geological trice, so how do we really
> know ANYTHING survived in Montana?
Laurie Bryant's study of Montana nondinosaur vertebrates found a total of more
than forty species that occur on both sides of the K-T boundary: 10 fish, 7
salamander, 3 frog, over a dozen turtle, 1 champsosaur, 4 lizard, 1 snake, 3
crocodilian. Exactly how many turtle taxa survived is unclear because turtle
fossils are extremely common in the study area, and their taxonomy is somewhat
muddled. I submit that while the replacement scenario may explain one or two
few species appearing both before and after, it does not explain the
of a combination of forty different species. Were _all_ of these species so
cosmopolitan that they occured both in Montana and in a refugium half a world
away? Rather unlikely, I think.
-- Jon W.