Re: Gary Larson and Purgatorius (was: stego time line, thagomizer)

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

Mickey Rowe wrote: 
>Gary Larson wrote there that he would like to apologize for including
>"cavemen" and dinosaurs in the same cartoon.  It was a good joke,
>though, so I think we can forgive him.

   Gary's apology for having Stegosaurus and cavemen in the same cartoon, 
not-withstanding, I thought this was the perfect opportunity to bring up the
subject of dinosaur-age primates.  There is some problematic evidence that
they actually existed. 
  The evidence for our order (Order Primates) living alongside T. rex comes
from a single site in Montana (called the Harbicht Hill Locality), where
screen-washing (i.e., "sieving") of sediments yielded a single tooth (a
molar) of the probable primate _Purgatorius ceratops_.  This is considered
by most mammal paleontologists to be the earliest known primate.  The animal
was small and is usually reconstructed as living in the trees.  It probably
locomoted like a tree shrew.  Dinosaur bones occur in the same
rocks as the Purgatorius molar.  Purgatorius is also found in the
earliest Tertiary rocks overlying the Harbicht Hill locality in the same
general area.  Some skeptics have claimed that the Harbicht Hill site is
actually Tertiary, but they are hard-pressed to explain the presence of
dinosaur bones at the site (they could possibly be re-deposited).  If
Purgatorius actually is a primate, and if the rocks that it was found in are
actually Cretaceous, then members of our own Order had to deal with dinosaurs. 
I only found a couple refs. on this dinosaur-age primate:
           Sloan, R.E. and Van Valen, L., 1965. Cretaceous mammals from
                Montana: Science, v. 148, pp. 220-227.

           Van Valen, L. and Sloan, R.E. 1965. The earliest primates: Science,
                v. 150, pp. 743-745.

The morphology of Purgatorius is better described from the Paleocene forms,
but I can't find the references for those.  I think Kenneth Fox has written
something on Purgatorius.

p.s.  If ever a 2nd species of Purgatorius is found in Cretaceous-age rocks,
I think it is only fitting that it be named Purgatorius thagi
(literally, "Thag's own Purgatory").