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Re: Senter et al. 2004 impressions



Tim Williams wrote-

> >True.  Senter et al.'s dissertation includes Avimimus and three
segnosaurs
> >however, and (though with a different character set) segnosaurs are basal
> >arctometatarsalians and Avimimus the sister clade to Oviraptoridae.
>
> So the Oviraptorosauria+Therizinosauroidea clade falls apart?  Is
> _Beipiaosaurus_ included in the analysis?

Yup.  Arctometatarsalia is (Segno(Troodo(Deinocheir(Alvarez,Ornithom)))) in
the dissertation (incidentally Senter's, not Senter et al.'s; heh heh... got
so used to writing the latter).  Beipiaosaurus was included, as were
Neimongosaurus and Erlikosaurus.  Sinornithoides and Byronosaurus were the
only included troodontids, and Sinovenator was not included either.

> Segnosaurs as arctometatarsalians...?  As remarked upon previously,
> troodontids and therizinosauroids share quite a similar dentition.  If
> alvarezsaurids are included in this clade, along with segnosaurs and
> bullatosaurs, then what we end up with is a major clade of
> non-hypercarnivorous maniraptoriforms (assuming troodontids were
> omnivorous).

Interestingly, in my latest run (210 new cranial characters added, though
not completely coded yet), segnosaurs are arctometatarsalians too.
Troodontids (including Sinovenator) are still paravians, though I haven't
incorporated Senter et al.'s corrections for Sinovenator yet.  As you can
see above, alvarezsaurids are arctometarsalians in Senter's phylogeny.

> I think it's worth noting _Bambiraptor_ is not coming out as sister taxon
to
> _Saurornitholestes_.  For a while there was a suggestion that the two
might
> be synonymous.  I think this was wishful thinking on the part of those
> (myself included) who despised the name _Bambiraptor_ and wanted to see it
> buried as a junior synonym of _Saurornitholestes_.  :-)   But at least it
> seems we can kiss goodbye to _Cryptovolans_.

Part of the reason may be incorrect referral of material to
Saurornitholestes.  Senter et al. included MOR 660 and RTMP 88.121.39 in his
OTU, as do I.  They include very few comparable elements to the holotype
(teeth, dorsal vertebrae, ribs, gastralia, caudal prezygopophyses), and the
Djadochta has two 'velociraptorines', so why can't the Judith River / Two
Medicine?  Also, the frontals of Bambiraptor are extensively crushed.

> A final note: I wonder what impact _Omnivoropteryx_ will have on
> maniraptoran phylogeny, especially vis-a-vis the topology of basal
> oviraptorosaurs?

In that latest run of mine, it was a caudipterid.  The short dorsal
premaxillary processes are quite different from the long ones in Sapeornis
and confuciusornithids.

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