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Re: Owenetta was Re: turtle origins?




Eric,
In all fairness, I believe the main challenge they made was to your statement that this evidence was being "suppressed". Owenetta is a procolophonoid----I classified them as Order Procolophoniformes in 1994, and yes they are anapsids. I listed Order Testudiniformes next, also as anapsids, and possible sister group to Procolophoniformes. That was pretty much universally accepted in the early 90's.
This viewpoint is not being suppressed, but it is now being challenged. The putative synapomorphies shared by those groups may be homoplastic (convergence), and now putative synapomorphies between testudines and various diapsid groups are being evaluated. I find that very exciting, and if turtles are diapsids, I will move them down next to Sauropterygiformes or whatever diapsid order they turn out to be related to.
------Ken Kinman
*****************************************************
From: ELurio@aol.com
To: kinman@hotmail.com, dinosaur@usc.edu
Subject: Owenetta was Re: turtle origins?
Date: Tue, 1 Aug 2000 08:35:01 EDT

I've been slammed over a comment I've made about the origins of turtles. Many
of you out there think I made the whole thing up and were chortleing about my
"foolish" pronouncements, and challenged me to put up or shut up.


Okay.

In the spring of 1991, Nature had a cover story on a Permian critter called
Owenetta, which was described by Robert Reisz and Michel Laurin, and
cladistically anaylized to show many points of similarity with turtles, so
much so, that Reisz and Laurin claimed Owenetta as a possible turtle ancestor.


Owenetta was clearly an anapsid.

eric l
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