Nicholas Gardner wrote-
Below is my rather early and tenative classification of Maniraptora (Passer + Enigmosaurus) that includes tyrannosaurs.
Maniraptora is already everything closer to Neornithes than to Ornithomimus. Enigmosaurus has no place in its definition (wasn't even considered theropod by Gauthier when he named the clade...).
|--"Enigmosauria" Keesey, unofficial
Hmm. Tom Holtz HAS used that term on the list. At last, I can stop writing "the segnosaur-oviraptorosaur group" when on a public forum!
| | |--Elmisauridae
Caenagnathidae is the correct name.
| |--Segnosaurinae (?=Enigmosaurinae)
| | |--Enigmosaurus
| | |--Erlikosaurus
| | `--Segnosaurus
Segnosaurinae has priority over Enigmosaurinae. Why oh why would you place Nanshiungosaurus and Therizinosaurus together? There's nothing comparable between the two. The former is known from vertebrae and a pelvis, the latter from fore and hindlimbs. I suppose if the "Chilantaisaurus" zheziangensis ungual does belong to the Nanshiungosaurus holotype, we could compare that, but I don't think you did...
| | |?-Alvarezsauridae
| | `---->Pygostylia
| `--Dromaeosauroidea (implied Matthew & Brown, 1922)
| | |--Archaeopteryx
| | `--Rahonavinae
| | |--Rahonavis
| | `?-Vorona
Eumaniraptora is (Deinonychus + Neornithes) so would be the node uniting Aves and Dromaeosauroidea in your phylogeny. Vorona is really much more derived than Rahonavis, even having a few euornithine characters. It's some type of ornithothoracine...
2) hyperextendable toe secondarily reduced and (?)lost in tyrannosaurs; L-shaped cannon bone of the foot; and the T-shaped bone of the jugal region (I can't remember what the specific bone is called but it was used to unite the tyrannosaurs with the ornitholestians and the allosaurs)
The bone is the quadratojugal. It's also dorsally expanded in Sinosauropteryx by the way.