Re: ceratopsians

[Stan Friesen <swf@ElSegundoCA.NCR.COM>]

 From: John Schneiderman <dino@revelation.unomaha.edu>
 > 
 > Has anyone worked out the systematics for ceratopsians?

Some work has been done - see "Dinosaur Systematics"
 > 
 > Some relationships to consider:
 > Triceratops/Torosaurus

I think this is unlikely.  The variation *within* Triceratops
corresponds to the gender variation in its relative Chasmosaurus.

 > Avaceratops/Monoclonius
 > Styracosaurus/Centrosaurus (or is it Eucentrosaurus)

Now, this is actually quite likely.  In the book I mentioned above
there is an article that suggest that Styracosaurus is the male
of *one* species of Centrosaurus, out of about 3-4 left after the
other "described species" are paired off into male-female pairs.
 > 
 > How does the new pachyrhinosaurs fit in?
 
It is a seperate form, probably derived from Centrosaurus.

swf@elsegundoca.ncr.com         sarima@netcom.com

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