RE: Archaeopteryx, Sinornithosaurus, Rahonavis, Unenlagia...]

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

> From: Josh Smith [mailto:smithjb@sas.upenn.edu]
>
> "Thomas R. Holtz, Jr." wrote:
> > Of course, this is only a problem if you are still actively
> searching for
> > direct ancestors, rather than sister taxa...
>
>     Oh, Oh right.  Bring systematics into it.  Right!  Well, be
> that way...
>     Unfortunately, you need to bring that argument to the Ji's
> and to Sun et
> al. and some others, who are calling for pulling _Archaeopteryx_
> out of the
> direct bird line because of the "Jurassic" age of Sihetun.

Indeed.  And to the Martin's, Feduccia's, and Ruben's, who somehow still
think that dromaeosaurids have been proposed as bird ancestors (when the
"standard model" considers them no more of bird ancestors than hyenas are
cat ancestors).

Not that Archie isn't a bad MODEL of a bird ancestor, but discovery of basal
Tithonian (or early) birds closer to Neornithes than to Archie would show
that the population called _Archaeopteryx lithographica_ is not the
population that gave rise to modern birds.

                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