RE: Euryapsida question

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> david peters
> Sent: Friday, May 20, 2005 10:12 AM
> To: dinosaur@usc.edu
> Subject: Euryapsida question
>
>
> So, is Euryapsida simply Ichthyosauria + Sauropterygia (sensu Caldwell 1996)?
>
> Or must it also include Proganosauria and Araeoscelis (sensu Williston 190? I 
> think)?

At present, I'm not certain if it has been formally phylogenetically defined in 
the published literature. I know that Merck has this
bigass manuscript lying around unfinished that would include definitions of a 
bunch of names in that part of the tree, but he's been
too involved in the day-to-day business of academic administration and such to 
get much progress on it lately.

As for those other creatues in particular: I can't recall where they fit on his 
tree, but I do not remember them being particularly
affiliated with the euryapsid clade. Many of the old features used to unite 
Euryapsida from the Williston era turn out to be much
more widely distributed among diapsids.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
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