Re: Purgatorius and Troodon

[chartiem@ERE.UMontreal.CA (Chartier Michel)]

> 
>   I wonder what "Purgie's" primary predator was?  Troodon?  _The Dinosauria_
> faunal list lists Troodon present in the Hell Creek Formation.  Were there
> any mammals that were tree-climbing predators in the Maastrichtian?  If not,
> perhaps Purgatorius was fairly safe in the trees (except of course, for
> predatory birds?).  A ground-dwelling mammal would have to contend with
> the small meat-eating theropods, but what about those mammals that spent
> 95% of their time in the trees?  Birds, snakes and falls from the tree
> probably culled most of the Purgatorius.  
>  Mesozoic mammal ecology is one of the most poorly-known parts of mammalian
> paleontology.
>   (Troodon vs. Purgatorius...battle of the Mesozoic super-brains!    :-)
> 
George asked if the Purgatorius tooth was Maastrichtian in age. Indeed
it is (or at least some think so).                                  
As for the validity of this taxon, I think it's fun to speculate about
the kinds of interaction such a critter might have had with the
contemporaneous dinosaurs, but my answer to this is: Forget it guys.
There's no such thing as a Cretaceous Purgatorius! ;-) Really, we
should wait until additional material is found (if ever) before
accepting the legitimacy of this fossil.
And I'm sure the new and amazing mammal fossils found by the AMNH guys
in Mongolia will shed some light on Mesozoic mammal ecology (at least
for this region at that time). Ralph Chapman mentioned the reference
to this a few weeks ago: Nature, April 28(?) 1995. Dinosaurs are also
discussed in this (in my opinion) too-short paper. Fantastic stuff!

Michel Chartier