Re: Are these characters accurate?

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Jason Michalak wrote-

> I just saw this website (http://www.evowiki.org/wiki.phtml?title=Aves) and
> wondered if what it is saying is accurate. It lists "Caudal tympanic
recess
> opens with the columellar recess", "Caudal maxillary sinus present",
> "Prenarial aspect of premaxilla elongate", "Prezygapophyses reduced
> distally", "Pes anisodactyl" and "Teeth with characteristic root
> constriction (after Martin et al. 1980, Gauthier 1986, Chiappe 1995 and
> Chiappe et al. 1996)" as supporting the bird node. From my last stupid
> question I'm pretty sure the first and second are not accurate, but are
the
> rest? The reversed hallux seems doubtful given some of the recent
discussion
> anyway.

It all depends on the rest of your phylogeny.
"braincase - posterior tympanic recess - opens into collumelar (= external
otic) recess" is known in mononykines and troodontids in addition to Aves.
"maxilla - ossified medial wall of caudal maxillary sinus - present" is not
definitely known in any non-ornithurine, but has been reported for
Gobipteryx.  See http://www.cmnh.org/dinoarch/2004Apr/msg00324.html for my
opinion of reports of this structure in other theropods.
"external naris - posterior displacement - prenarial length" is larger in
Aves (>15% of preorbital length) than in most other theropods except
enigmosaurs.
"caudal vertebrae - prezygopophses - length <40% of centrum" is also found
in Bagaraatan, compsognathids, Coelurus, alvarezsaurids, therizinosauroids,
Protarchaeopteryx, caenagnathoids and basal troodontids.
"metatarsal I - shaft torsion - twisted to cause hallux to be directed
medially to posteromedially" is only known in pygostylians at the moment.
"teeth - mesiodistal width of basal crown and root - all subequal (0); at
least some with wider crown than distal root" is known in Richardoestesia,
Compsognathus, Pelecanimimus, mononykines, enigmosaurs, troodontids and
Microraptor in addition to birds.

Mickey Mortimer
Undergraduate, Earth and Space Sciences
University of Washington
The Theropod Database - http://students.washington.edu/eoraptor/Home.html