Re: sauropods & ornithischian relationship

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

>From: Don Squires <pp000723@interramp.com>
 > 
 > The sauropod dinosaurs and their prosauropod kin are classified in the same 
 > suborder as theropods, i.e., saurischia. Is this classification based only 
 > on the 
 > shape of the hip?

No, there are other factors, ranging from general to very detailed.

The ornithischians have a number of specializations, such as
few or no teeth on the premaxilla, which are rare in saurischians
(the main exception being the segnosaurs).

Also, each group has a goodly number of detailed (minor) anatomical
specializations found in most members.  Thus the segnosaurs are
recognized as theropods by their sharing with theropods a number
of details of the legs and vertebrae, despite some overall
similarities to onithischians.
 > 
 > Is it possible that the sauropodamorpha are more closely related to the 
 > other 
 > herbivorous dinosaurs classified as ornithischians than to theropods? I seem 
 > to 
 > recall reading this somewhere.

This has been suggested, but not widely accepted
 

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

The peace of God be with you.