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Re: Cretaceous taeniodont
John Bois wrote:
How many species need to be
above, say, one kg. before we can say predation and/or competition was no
longer keeping mammals small?
Hmmm... maybe the size increase has little to do with the predators
themselves (presumably theropods), but something that the mammals started to
do differently. Perhaps mammals got smarter, or faster, which allowed them
to better evade capture.
There is a tendency, I think, to view Mesozoic mammal evolution exclusively
through the prism of dinosaurian dominance. Of course, it was undoubtedly
the dominance of dinosaurs that kept mammals to growing up to sheep- or
elephant-sized in the Mesozoic, as they did in the following Cenozoic (after
the big dinos went bye-bye). But the shift from shrew-sized mammals to
wolverine-sized mammals in Cretaceous mammal dimensions (in North America,
anyway) may have been due to some anatomical innovation(s) in the placental
lineage. Better sensory capabilities, keenr intelligence, better locomotory
abilities... I dunno. But I don't think we should assume that it was always
external factors that were keeping mammals small (e.g., quality of the
predators) in the Mesozoic.
Would one more do it? Two?
Also, if any of these mammals were burrowers what are the chances we would
find their burrowers?
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