Re: sauropod plates

[George Engelmann <engelman@cwis.unomaha.edu>]

I believe the sauropod plates described by Czerkas were based on material from
Howe Quarry in the Morrison Fm. in Wyoming which was opened recently by 
commercial collectors. They were not bony but are preserved as skin
impressions. Apparently skin impressions were abundant in the quarry when it
was excavated by Barnum Brown, and much was destroyed then to get at the bones,
which are at the American Museum (in a hot room thanks to high radon emissions).
I think the quarry produced mostly Diplodocus, so that would be the basis for
the identification with some uncertainty because of lack of direct association
of the skin with diagnostic bones. Czerkas' paper was in Geology:
 Czerkas, Stephan A., 1992. Discovery of dermal spines reveals a new look for
sauropod dinosaurs. Geology, 20 p. 1068-1070

George Engelmann
engelman@unomaha.edu