Re: Tyrannosauroids and dromaeosaurs

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

David Marjanovic wrote-

> > I changed the "double-headed quadrate" character into two characters-
> > "quadrate contacts squamosal and prootic or opisthotic" and "proximal
> heads
> > of quadrate widely separated".  Did you know troodontids have the
former?
>
> No...

Yup.  Both Sinornithoides (Russell and Dong, 1993) and Troodon (Currie and
Zhao, 1993).

> > I wonder why Maryanska and Osmolska (1997) made
> > such a big deal about caenagnathoids having it.
>
> Because they have the latter... don't they?

No, not really.  They have two articular surfaces, but they aren't separated
into two separate heads.  I think I'll make an intermediate state for this
sometime (like in Clarke's bird analysis), but it's hard to determine for
nearly anything.

> > Nah, segnosaurs are just drawn more basally quite often.  Sometimes as
> > arctometatarsalians.  Now Enigmosauria exists again, though
Beipiaosaurus
> > and Erliansaurus form a clade in the basal Coelurosauria and
> Therizinosaurus
> > is directly basal to avepectorans.  Stupid segnosaurs, it's so hard
> keeping
> > them together.  Damn the ghost of Ken Kinman! ;-)
>
> :-D Cool. Well, the pelvis etc. will fix them, I predict.

Maybe.  That and the pes.

> > [...] now everything's back to normal in that area,
> > except that troodontids are avialan.
>
> Er...
> +--dromies
> `--+--Archie
>    `--+--troodontids
>       `--usual birds
> ?

Nah, it was-
|--Deinonychosauria
`--+--Troodontidae
   `--+--Scansoriopterygidae
      `--Aves
If you recall, troodontids were always avialans in my old analysis (along
with alvarezsaurids and Avimimus).

> Wait.
> What does the strict consensus look like? :-) Maybe *Anserimimus* just
> reduced the polytomies in some parts of the tree, created new ones in
> others, and thus changed the 90 % majrule tree without changing the strict
> consensus all that much.

The strict consensus is usually crap, with so many taxa codable for ~10% of
characters, and so much homoplasy.  Hopefully when I'm done it will be
different.

> > > Why not *M. gui* and *C.* as sistergroups?
> >
> > - sternum length (anterior median tip to posterior median tip) width
> > (narrowest width across costal margins, or greatest width for those taxa
> > without costal margins) ratio > 170.
> > - [...].
>
> Cool. But in that character, you're measuring two completely different
> widths depending on whether there are costal margins or not.

Good observation, and one which has been ignored since 1993 at least
(Mononykus, Liaoningornis?).  Have any recommendations as to how to fix it?

> > New 90% majority rule-
> > [...]
> >                      `--+--Deinonychus
> >                         `--Unenlagia
>
> *Archaeornithomimus* makes *Unenlagia* jump... this sounds like the strict
> consensus is pretty unresolved. Is it? :-)

Anserimimus does. :-)  Yeah, the strict consensus around deinonychosaurs is
usually unresolved.

> > Or yanornithids being monophyletic at all.
>
> Never got them that way -- but I didn't include the sternal characters
that
> support their monophyly, unlike you!

I actually haven't included Clarke's "posterior sternal fenestrae"
character, or the "flat furcular base" character that's supposed to unite
Songlingornis with Yixianornis.

Mickey Mortimer