RE: Stenopelix valdensis

[Michael Mortimer <mickey_mortimer111@msn.com>]

Michael Lange wrote-

> I heard that Sullivan has recently made Stenopelix an Ornithischia indet. 
> I've seen the specimen >myself some years ago on display at the small 
> Geological Museum in Goettingen. The skull is not >present, but should have 
> been preserved when the quarry workers found the skeleton (when I >recall 
> correctly). Still, its a nice and interesting specimen. What are the 
> reasons why Sullivan says >its no Marginocephalian anymore.

Because few pachycephalosaurs preserve good postcrania, so he's far too 
cautious about referring postcrania to the clade (if he can't prove that 
most pachycephalosaurs had a trait, he considers the trait 'weak').
Also he questioned the absence of pachycephalosaur postcranial 
synapomorphies in outgroups, with no examples to show why he questions it.
Finally, he likes Coombs (1979) outdated idea of pachycephalosaurs being an 
ankylosaur sister group better, and Stenopelix lacks a pelvic character 
those two clades share.  Needless to say, Yinlong nicely blows that proposed 
relationship out of the water.
So basically Sullivan's reasons are worthless and should not be given any 
weight.

Mickey Mortimer