Re: My Phylogeny: Growing Science...

["Mickey Mortimer" <Mickey_Mortimer11@msn.com>]

David Marjanovic wrote-

> > > Do caenagnathoids really have the derived condition?
> >
> > I have them coded as being primitive, but this was probably from a data
> > matrix.
>
> Impossible to tell from http://www.dinosaurclass.com/dino0905.htm, isn't
it?

Oh, caenagnathOIds.  I was speaking of caenagnathids.  Oops.  Um,
oviraptorids definitely have the primitive condition- look at the nesting
Citipati.  Its ischia are strongly attached to each other.

> So 0 for Dromaeosauridae and *Sinornithosaurus*, ? for Segnosauria and
> Bambiraptor?

That's all I can tell.  Some data matrix probably has segnosaurs coded as
having a single-headed quadrate.  I think Clark et al. (1994) would have
made a big deal about it if the quadrate was double-headed in Erlikosaurus,
but we'll see.

> So "Antitrochanter absent (0), small (1), big (2)"? Or is there a need to
> quantify that?

I'm uncertain enough about how I'm going to distinguish the "prominent"
antitrochantor from the "non-prominent or absent" antitrochantor once I get
to that character in my accuracy re-evaluation.  I wouldn't recommend making
it more complicated until you look at the evidence yourself.

Jaime Headden wrote-

> Caenagnathids most certainly do not have interdental plates. And frankly,
neither do
> troodontids. I have no idea where the latter came from, but I feel that I
am partially
> responsible in that I suggest to Mickey somewhere that the medial alveolar
wall of the
> dentary in *Caenagnathasia* was analogous to the condition of interdental
plates, as in
> Troodontids.

You said homologous.  _Homologous_! ;-) Oh well, these structures really
need a detailed study.

> and Mickey replied:
> <I have them coded as being primitive, but this was probably from a data
matrix.>
>Probably. No complete braincase is known for caenagnathids (as described
anyway).
> However, oviraptorids, *Caudipteryx* (unknown in *Avimimus*) and
*Erlikosaurus* all > have a neat little row of the two exits for the fifth
cranial nerve (V^1 and V^2,3), the
> seventh, and the dorsal tympanic fenestra. It is therefore parsimonious to
assume that
> caenagnathids and *Caenagnathasia* have the condition as well. Code
caenagnathids as - > until data can be recovered to verify or falsify my
hypothesis.

Actually, this was all a discussion about the ischial symphysis, not cranial
nerves :-).  I can't tell from Currie (1988) or Sues (1997) whether
Chirostenotes had an ischial symphysis.

Mickey Mortimer