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RE: New paper on Caudipteryx & cursoriality in Nature



> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> ekaterina amalitzkaya
>
> One thing that was really clear from teh Jones et al paper, is that they
> possibly have bird are not theropods as their null hypothesis. They end
> their paper saying that  Caudipteryx is the only unambigously feathered
> theropod, so that means archaeopteryx is not a theropod by there
> definition.
> So clearly the paper was written with an agenda.

Then again, Ruben and his students have never adopted a
phylogenetically-based taxonomy, so this could also be interpreted as the
"old-fashioned" use of the term: i.e., "dinosaurs" = "non-avian dinosaurs"
and "theropod" = "non-avian theropod".  I'm willing to give them the benefit
of the doubt here.

> But I would like to ask whether their observation in the methods section
> that juvenial non-avian theropods have ratios closer to the birds
> or within
> the bird range supports birds being paedomophic theropods?

That might indeed be a possibility.  Also significant, though, is the fact
that the two specimens they reject from use are among the most complete
dromaeosaurid and troodontid skeletons ever fond: i.e., they are from the
taxa closest to the origin of birds, and in fact taxa which the Gatesy and
Middelton 1997 study find plot morphometrically close to birds in terms of
hindlimb scaling.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796