Re: Dermal spine

[tlford@ix.netcom.com]

Jonkeria@aol.com wrote:
> 
> Just a quick question about an ornithishian amidst all this feathered
> theropodmania-I have just read Lucas' 1901 description of "Stegosaurus"
> (?Polacanthus) marshi, and in it he makes the following statement:
> "A dermal spine, found by Mr. J. B. Hatcher, in conjunction with the remains
> of Triceratops, and regarded at the time as belonging to that genus, may very
> likely have come from the species under consideration" [S. marshi]
> 
> Now, I doubt that this Upper Cretaceous find is S. marshi, but what is it? Is
> it a badly weathered Triceratops horn, or true ankylosaurian dermal armor,
> possibly from Edmontonia?
> 

More then likely it was the squamosal spine of Stygimoloch, YPM  335.
I'm doing a write up for it in Prehistoric Times, and why
pachycephalosaurs didn't butt heads. 

There are two new articles about this, one by Ken Carpenter the other by
Goodwin et al.


Carpenter, Ken, 1997. Agonistic behavior in pachycephalosaurs
(Ornithischia: Dinosauria): a new look at head-butting behavior.
Contributions to Geology, University of Wyoming, Volume 32, Number 1:
19-25.

Goodwin, Mark B., Emly A. Buchholts, and Rolf Johnson, 1998. Cranial
anatomy and diagnosis of Stygimolch spinifer (Ornithischia:
Pachycephalosauria) with comments on cranial display structures in
agonistic behavior. Journal of Vertebrate Paleontology, Volume 18,
Number 2: 363-375.

Tracy