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Re: Nocturnal crocs?




On Fri, 24 Aug 2001, Jerry D. Harris wrote:

> 
> Must've missed the post awhile back about the largest known  Mesozoic mammal 
> from the _Early_ Cretaceous:

I based my statement on Lillegraven from Mesozoic Mammals.  This is not to
say
there were exceptional big mammals at other times, just as there are now
exceptionally big birds but generally birds are relatively small.  
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.