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Re: K-T selection event



>Random musings . . .
>
>I've never entirely bought into the notion of a meteor strike causing
>the terminal-Cretaceous extinctions.  So I keep thinking about other
>things that might have done it.  My main question is: why did the
>extinction occur the way it did?  Why were dinosaurs wiped out and not
>mammals or birds?  Why mosasaurs and not sharks?  Why ammonites and not
>nautiluses?

(discussion of metabolism gradations deleted)

>Comments, thoughts, ideas, anyone?
>
>-- JSW

        I'd be willing to accept an asteroid (or asteroid shower) as the
last straw in the extinction of the Mesozoic megafauna.  The Daccan
eruptions, and maybe even the climatological after-effects of the breakup
of the supercontinents may have contributed.  But as to the survival of
mammals and birds, I think it had something to do with the fact that they
were seed-eaters and insectivores.  Cockroaches and plants with small seeds
obviously survived, and so then did the animals that fed on them.  How many
insect- or small seed- eating dinosaurs were there?

bruce



        "Dammit, Philbert; what kind of a lepidopterist are you?  For god's 
sake,
man; stand up to them!"