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RE: Stormbergia dangershoeki, new Early Jurassic ornithischian from South Africa



> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> T. Michael Keesey
>
> > Here's my problem with the current stem-based definition of Ornithopoda...
> > What if current euornithopodan taxa ("hypsilophodontids", iguanodontians)
> > form a paraphyletic array between heterodontosaurids and marginocephalians.
> > If you look at Fig. 25 of Butler (2005), this would not require a major
> > shift in topology.
> 
> Yes, but that's a ... septachotomy? The lack of resolution there
> indicates he was not looking closely at relationships within that
> clade.

Actually, we don't know that it is...

One thing that I would REALLY like to see more researchers do is show consensus 
trees (or subtrees) other than strict and majority rule. I haven't had time to 
strip out the data and run it myself, so I don't know what the precise details 
of the topology that was recovered. It might well be that everything but 
Jeholosaurus is stable, but the latter is popping out as as the sister taxon to 
each of the "hypsilophodonts", as the sister to Iguanodontia, as the sister 
group to Marginocephalia, and as the sister to Cerapoda as a whole. The strict 
consensus would indeed be the heptachotomy shown.

Still, this is one damned important paper, and part of a series of damned 
important papers that will help sort out the mess of little bipedal 
ornithischians. Honestly, the cladogram he found makes a heck of a lot of sense.

                Thomas R. Holtz, Jr.
        Senior Lecturer, Vertebrate Paleontology
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
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