Re: Coelurosaur phylogeny

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

Nick Gardner wrote-

> Out of curiousity, do you code Dromaeosauridae, Ornithomimosauria,
> Alvarezsauridae, Segnosauria, and the Troodontidae as OTUs or do you have
> them split up as multiple OTUs and you've just chosen not to reveal the
> internal phylogeny of those clades onlist?

I have them all split up into multiple OTU's.  Unfortunately, some coded
taxa aren't known by enough cranial, axial and pectoral material to be
included in my preliminary analyses (they would form large polytomies).
Taxa complete enough to be included in the analysis that generated the
listed tree-
Dromaeosauridae- Achillobator, Dromaeosaurus, Utahraptor, Deinonychus,
Velociraptor, IGM 100/1015, Saurornitholestes.
Ornithomimosauria- Pelecanimimus, Harpymimus, Garudimimus,
Archaeornithomimus asiaticus, Ornithomimidae.
Alvarezsauridae- Alvarezsaurus, Patagonykus, Mononykinae.
Segnosauria- Alxasaurus, Neimongosaurus, Segnosaurus, Erlikosaurus.
Troodontidae- Sinovenator, Sinornithoides, Byronosaurus, Saurornithoides
mongoliensis, Saurornithoides junior, Troodon.
Taxa not complete enough to be included yet, with number of characters coded
for in parentheses.
Dromaeosauridae- Adasaurus (2), Pyroraptor (9), Variraptor (18).
Ornithomimosauria- Deinocheirus (6), "Grusimimus" (12).
Segnosauria- Beipiaosaurus (19), Erliansaurus (10), Nothronychus (24),
Nanshiungosaurus brevispinus (19), Therizinosaurus (6).
Troodontidae- IGM 100/44 (15).
The internal structure of the clades is normal for the most part, though
Alvarezsaurus likes to clade with mononykines, and velociraptorines are
usually paraphyletic to dromaeosaurines.  Archaeornithomimus jumps around
inside Ornithomimosauria, and Neimongosaurus is usually in the
Oviraptorosauria (despite being coded for 48 characters).

> I just noticed now that the Arctometatarsalia is the sistergroup to
> Enigmosauria in your analysis.  I feel stupid for not catching it
> previously.  What characters support this relationship or is that
something
> you don't want to share just at the moment, which might be understandable?

You shouldn't feel stupid.  Previously, enigmosaurs weren't
maniraptoriformes at all.  Only after including the additional bird taxa did
this change.
Arctometatarsalia is diagnosed by-
- palatal shelves of maxillae contact.
- coronoid absent.
- surangular foramen absent.
- cervical epipophyses placed anteriorly to postzygopophyseal facets.
- posterior cervical postzygopophyses much longer than prezygopophyses.
- ventral edge of anterior articular surface of cervical centra three and
four with a sharp raised rim.
I don't care much about the results being known now because I expect them to
change by the time I get more characters and taxa added.

> >       `--+--Protarchaeopteryx
> >          `--+--+--Archaeopteryx
> >             |  `--Wellnhoferia
> >             |--Scansoriopterygidae
> >             `--+--+--Rahonavis
> >                |  |--Shenzhouraptor
> >                |  `--Jeholornis
> >                `--Pygostylia
>
> What supports the _Rahonavis_ + _Shenzhouraptor_ + _Jeholornis_ clade?

In the newest trees (after adding Utahraptor and NGMC 91), Rahonavis is
basal to Jeholornis and Shenzhouraptor (which are sister taxa) + Pygostylia.

Mickey Mortimer