My phylogeny etc. (was RE: SVP review (the short version))

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Rob Gay

I'll try to get my own big write-up done later this week.  Incidentally, the
DML was VERY well represented there; good to see you again, or to meet you
in person for the first time.

> HP Holtz gave a talk on tyrannosaur phylogeny, which was very
> interesting,
> and placed them closer to ornithomimosaurs than any other group.

Actually not, for once.  The phylogeny (85 taxa, 642 characters: I'll see
about posting some of the trees on my website later this week since this
will not be the final published version, as there are some really important
taxa in the publishing pipeline that I want to include) finds
Tyrannosauroidea to contain tyrannosaurids, Eotyrannus, Stokesosaurus, and
Dryptosaurus; that tyrannosauroids are the sister taxon to
Maniraptoriformes, which is itself a trichotomy of Ornithomimosauria,
Coelurus, and Maniraptora.  Maniraptora breaks down into:

"Enigmosauria"
        Oviraptorosauria
        Therizinosauroidea
Paraves
        Alvarezsauridae
        Eumaniraptora
                Protarchaeopteryx
                Avialae
                Troodontidae
                Dromaeosauridae

> It also
> found ceratosaurs to be paraphyletic, which is of great intrest to me.

When collapsed down, the basal structure I found was:
Herrerasauridae
"eutheropods"
        Coelophysoidea
        Neotheropoda
                Ceratosauria
                Tetanurae
                        "Szechuanosaurus" zigongensis
                        an unnamed clade (for which Novas' "Avipoda" might fit)
                                Spinosauroidea
                                Avetheropoda
                                        Carnosauria (containing Siamotyrannus!)
                                        Coelurosauria
                                                an unresolved polytomy of basal 
forms
                                                Tyrannoraptora
                                                        Maniraptoriformes
                                                        Tyrannosauroidea

Nearly every taxon was coded at the genus/species "level" (except those that
were redundant for the characters used in the analysis: i.e., Mononykus,
Shuvuuia, and Parvicursor were coded as a single Mononykinae; Baryonyx &
Suchomimus as a single Baryonychinae; etc.)

> Another first rate talk was about the vertical running origin of flight
> theory...wow, there was more appluase for this talk than any
> other...it was
> really astounding in my opinion.

It was, in my opinion, **the most important talk given at SVP in all my
years going there**.  It answered a LOT of questions; it was extremely
well-supported; and it had really cool video.  More on this later
(particularly when I see if it is/when it will be kosher to go into the
details)

> Also among good talks was Hans-Dieter Sues

Robert Reisz actually gave that talk, which was still excellent.

> talk on
> _Longisquama_...blatantly
> stating that (as the title suggested) that _Longisquama_ does not have
> feathers. He demonstrated the structures were hollow, 3D
> structures in life,
> and when the animal dies, the vanes collapsed and infilled with sediment.

Robert & Hans-Dieter have pretty well-demonstrated, in extremely good
detail, that the elements that Longisquama had have as little bearing on the
morphology or origin of feathers as the paddle of a plesiosaur has to do
with the pteroid bone of a pterosaur.  Sure, both Longisquama longscales and
coelurosaurian feathers are modified integumentary structures, but they are
modified in radically different modes.

                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