[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Dinosauricon Phylogeny: complete
T. Michael Keesey wrote-
> This is an interesting grouping.
> > # *Achillobator*
> > # *Adasaurus*
> > # *Dromaeosaurus*
> > # ? *Unenlagia*
> > # *Utahraptor*
And one supported by few characters, none known in all members.
Achillobator, Dromaeosaurus and Adasaurus all have a stout pedal phalanx
II-2. Achillobator shares double dorsal pleurocoels and some primitive
characters (presumedly reversals) with Utahraptor. Unenlagia's ilium has a
few characters in common with Achillobator, but not Adasaurus.
> And then figure out where the non-type specimens go....
> (No generic name has ever been proposed for _bavarica_, right? Is it
> that it allies with one of the other three species to the exclusion of the
> other two?)
Elzanowski (2002) says neither the Maxberg or Harlaam spacimens can be
assigned to a species. Personally, I'm doubtful as to the validity of A.
siemensii and A. bavarica.
Nick Gardner wrote-
> CMIIW, but doesn't the presence of more than 4 teeth still
> represent itself as possibly synapomorphic for Largirostrornis and
Assuming Hou's correct about premaxillary tooth count, yes.
> Can you provide a reference for the original description of Nanantius and
> "N. valifanovi", as well as for the synomization of Gobipteryx with "N.
Molnar, 1986. An enantiornithine bird from the Lower Cretaceous of
Queensland, Australia. Nature 322 736-738.
Kurochkin, E. N. (1996) A New Enantiornithid of the Mongolian Late
Cretaceous, and a General Appraisal of the Infraclass Enantiornithes
Palaeontological Institute of the Russian Academy of Sciences, Moskou,
Special issue 60 pg.
Chiappe, Norell and Clark, 2001. A New Skull of Gobipteryx minuta (Aves:
Enantiornithes) from the Cretaceous of the Gobi Desert. American Museum
Novitates 3346 1-15.
David Marjanovic wrote-
> > - maxillary fenestra present (P)
> Unknown in *Iberomesornis*... and *I.* appears to be crucial for keeping
> *P.* and *L.* in Enantiornithes, because it's always more basal when
> any structure in that part of the tree.
No reason not to include the character.
> > - posteromedial sternal process absent (P)
> > - posteromedial sternal processes not pointed (L)
> > - broad posteromedian sternal process (P)
> Could be one character: sternum not particularly well ossified. Again hard
> to compare with *Iberomesornis*.
The first two perhaps, the third, no. If anything, a narrow posteromedian
process would be less ossified. Iberomesornis has such a narrow process,
but the condition of its posteromedial processes is unknown.
> They have an acrocoracoid?!? In my matrix, nothing else except *Anas* and
> *Ichthyornis* would have had that. Because I didn't know more about the
> distribution of this character, I ignored it. Looks like I really
Uh, of course they have an acrocoracoid. It's just a modified coracoid
tubercle. Most ornithothoracines have one.
> > - ventral position of a small, short and oval humeral articular head.
> Oval? Like globose, as opposed to "cranially concave and caudally convex"?
No, I think the shape is in anterior view, not proximal view.
> > - long and thin manual digit II-2.
> IMHO *Otogornis* only preserves digit I.
Tim Williams wrote-
> * The inclusion of _nomina dubia_ (e.g., _Palaeoscincus_, _Pteropelyx_,
> _Agathaumas_) is probably just a waste of space, and giving them equal
> billing to the valid genera gives them the illusion of legitimacy. Most
> based on teeth or scrappy postcranial material, and named at a time when
> was routine to give a new name to teeth and scrappy material.
As Mike said, nomen dubium is a largely subjective designation. Even teeth
might be diagnostic once studied in depth. Smith's (2002) unpublished
dissertation is a great start.
> I had thought _Minmi_ lay outside the nodosaurid-ankylosaurid dichotomy;
> I may be thinking of an old phylogeny. _Struthiosaurus_, I thought, was
> inside the Nodosauridae.
For Minmi- not according to Hill et al. (2003), the most comprehensive
ankylosaurian phylogenetic analysis to date.
For Struthiosaurus- not according to Vickaryous et al. (2001), the most
extensive phylogenetic analysis including the taxon.
> I don't believe _Avaceratops_ is a centrosaurine; it appears to be
> the Centrosaurinae-Chasmosaurinae dichotomy.
Forster (2002) disagrees.