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Re: Nocturnal crocs?



> But look, there is a placental, a marsupial, and a multituberculate (the
> size of a marmot, badger, and mink respectively all in the Lancian.  This
> was a unique
> situation interms of Late Cretaceous times--and this all occurred
> right at the very latest Cretaceous.  Up until this time (in the
> late C.) almost all known
> mammals were shrew-mouse size.  This represents (to me) a relaxation in
> size constraints. For starters, no placentals are known to be that
> big.  I'm not sure what statistical statment could be made to make this
> more meaningful.  But surely there is a phenomenon to describe.

I'm not sure that there is a phenomenon. 3 big mammals instead of 1 in one
spot may not be statistically significant and tell more about the quality of
the fossil record. For why there weren't any big placentals (and marsupials)
before -- how old is Eutheria in the first place? End-EK?
How big are *Deltatheridium* and the "Gurlin Tsav Skull" (a stagodontid),
both from before-end LK Mongolia?
What should have caused the relaxation in size constraints?