RE: Pachy found!

["Rafert, John" <JRAFERT@xray.indyrad.iupui.edu>]

Out of curiosity, has the pachy skull been subjected to computed tomography. 
If so, what were the results regarding the structure of the dome. Is it 
truly solid? Thanks for the info.

John Rafert
jrafert@xray.indyrad.iupui.edu
office phone: 1.317.274.5255
fax number: 1.317.274.4074

 ----------
>From: dinosaur
To: Multiple recipients of list
Subject: Pachy found!
Date: Monday, February 06, 1995 9:52AM


Thanks for the info Ken: In my messages regarding the deal there were
some qualifications:

1) That it be articulated and have both cranial and post-cranial
material (although the former may be made uncritical if the latter is
good enough.

2) That it be deposited in a museum.

and 3) that I be allowed to describe it (or be part of the description).

It sounds like 1) is in good shape, and I assume 2) will happen also.
Dale describing it, however, makes 3 problematical. However, I'm going to
write Dale and see if I can offer some of my own expertise to the project
of describing the material - basically morphometrical analysis for the
comparison of the specimen with other stuff, especially the cranial stuff.
If I can get in on the work, then I'll have to find the type of beer
fridge I was talking about and get it to North Dakota. If not, it is still
an event worth celebration, so I'll contact the collector and figure out
if he'd like a case of beer, or a good bottle of scotch, etc. The offer
was part enticement, part celebration and part open bribe to allow me to be
part of the description. I'll let you know how it turns out. Hopefully,
Dale isn't quite done yet. I'm hoping it isn't a new species, actually,
because I think getting multiple specimens of rare species will be more
instructive about the biology of pachys. Multiple domes of S. validum
allowed us to describe the best case of sexual dimorphism in the
non-avian dinosaurs. It's pretty ironinc that the dome is missing, it's
the one part that is almost always the only thing found. It'd be funny
if it's dome is sitting in a museum somewhere.

This brings an interesting question up for discussion, why mostly just the
dome? It seems fairly straight-forward taphonomically - it being this robust
bowling -ball that can withstand a lot of transport. But why are pachys
so rare otherwise? Conventional wisdom has them in the uplands, where
we seldom get much of any deposition going on. The domes then make the
transported trip down the streams/rivers. Somehow I'm skeptical of this
since I don't think much transport would be needed to make them
unidentifiable. So any ideas gang? Perhaps they'll be rare until
we start finding bone-beds of the things. With all the finds of T rex
lately, I'm getting the feeling that it wasn't quite as rare as conventional
wisdom had it until recently.

Ralph Chapman