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RE: Greg Paul's new (or newly named) iguanodonts



> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of David Marjanovic
>?
> > And really: those who have argued for a "thecodont" origin 
> since the 
> > 1970s (Tarsitano, Martin, etc.) argued for relationships 
> with animals 
> > that thecodont workers (Charig, Parrish, Chatterjee) would not 
> > consider thecodonts at all!!
> 
> Considering avicephalans "thecodonts" was made possible by 
> the absence of tree-thinking. In precladistic times, all but 
> maybe the real specialists on any group didn't imagine a 
> group as a twig, they imagined it as a blob on a romerogram. 
> Such blobs lack internal structure; the fact that no 
> avicephalan fits into the "thecodont" tree didn't matter 
> because people simply didn't think of it. At best, blobs on a 
> romerogram consist of more blobs with stippled lines between 
> them; adding one more little blob for *Megalancosaurus*, 
> supported on a stippled line that originates from a 
> free-floating question mark, is no big affair (if only you 
> believe that
> *Megalancosaurus* has The Defining Feature, the antorbital fenestra).

While I agree with much of what you said, in actual fact the avicephalan
types were only considered thecodonts by the "anti-dinosaurian origin of
birds" folks. You didn't see them mentioned in the works of those who
actually dealt with the thecodont blob (to which I should add the
rather-not-terribly-obscure-so-how-the-heck-did-I-leave-them-off Romer,
Colbert, and Benton!!)

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Earth, Life & Time Program, College Park Scholars
http://www.geol.umd.edu/~jmerck/eltsite/
Fax: 301-405-0796

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA