Re: Re: Removing segnosaurs from Theropoda

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

>From: Thomas_R_HOLTZ@umail.umd.edu (th81)
 > >
 > >And, pray, what other name is available for stem-archosaurs?
 > >
 > Nonmonophyletic groups do not need to be named.

That is where we disagree.  I think they do.  So does Olshevsky.
 > 
 > "Thecodontia" as commonly used is a doubly (or even triply)-paraphyletic 
 > term.

Yep.  As I defined it in the previous message it is triply para-
phyletic.  Defined as George Olshevsky does, it is doubly so.

 > Under most archosaur workers phylogenies, the majority of the classical
 > "thecodonts" (rauisuchids, aetosaurs, parasuchians, etc.) are recognized as
 > sharing a more recent common ancestor with crocodiles than with the dinosaur
 > (bird) + pterosaur clade.  This group is called Pseudosuchia, or (for those
 > who'd prefer crocodiles not be among the "false crocs") Crurotarsi.

I would make the Pseudosuchia one of the orders within Thecodontia.
[But defined as a paraphyletic group, excluding the crocodiliforms].

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.