Re: Tyrannosaurus "Scavenger vs. Predator" debate (joke)

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

Tim Williams wrote-

> >Don't forget Dryptosaurus, and quite possibly "Chilantaisaurus"
maortuensis
> >and Bagaraatan.
>
> Which particular characters put these guys in with the tyrannosaurs?

Progressively more closely related to tyrannosaurids in tree 1-
Dryptosaurus-
- enlarged surangular foramen.
Bagaraatan-
- enlarged surangular foramen.
- foramen aerum penetrating articular.
- articular with elongate medial, posteromedial or dorsomedial process.
- number of caudal vertebrae with transverse processes less than 16.
"Chilantaisaurus" maortuensis
- fused interdental plates. (reversed in tyrannosaurids)
- sagittal crest on parietals.
- occipital condyle constricted.

> >Itemirus is always a troodontid oddly.
>
> Now this is intriguing - what characters link _Itemirus_ with the
> troodontids?

Well, I added Itemirus (8/243 characters) and it changed the topology.
Interesting features include basal ornithomimosaurian Anserimimus, basal
maniraptoran alvarezsaurids, oviraptorosaurs paraphyletic to segnosaurs,
with Avimimus the sister taxon of Erlikosaurus(!).  Anyway, Itemirus is
placed as the sister taxon to troodontids more derived than IGM 100/44 and
Sinovenator based on-
Maniraptora
- branches of internal carotid artery entering hypophyseal (pituitary) fossa
through common opening (also in tyrannosaurids).
- foramen magnum >90% of occipital condyle width.
Paraves
- foramen magnum taller than wide (also in some tyrannosauroids).
sister to derived troodontids
- occipital condyle constricted (also in tyrannosauroids).
So as you can see, it's the large occipital condyle that's causing Itemirus
to clade with non-tyrannosauroids.  Size-related perhaps?

Mickey Mortimer