Purgatorius and Troodon

[Phillip Bigelow <n8010095@henson.cc.wwu.edu>]

Tom Holtz wrote:
>So, Thag's forebears were safe from stegosaurian tail spikes.  But watch
>out for ankylosaurid tail clubs and nodosaurid lateral spines..

  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!    :-)