Re: the first raptor

["Mickey_Mortimer11" <Mickey_Mortimer11@email.msn.com>]

Tim Williams wrote-

> I wonder if this last character (and perhaps others shared between
> _Utahraptor_ and _Achillobator_) is size-related?

I doubt it.  After all, it's mostly reported in small taxa (Microvenator,
Chirostenotes, oviraptorids, Variraptor), isn't common in tyrannosaurids,
and is not found in big carnosaurs, spinosauroids, etc..

> Are _Utahraptor_ and _Achillobator_ more primitive than _Microraptor_ and
> _Sinornithosaurus_?  I would guess that "primitive" in the context of
> eumaniraptorans is extremely relative, since in many analyses the basal
> dromaeosaurids are closest to the origin of birds.

I think it highly probable Utahraptor and Achillobator are indeed more
primitive than Sinornithosaurus and Microraptor, as the latter two appear to
be basal avialans.  "Utahraptorines" seem to be either deinonychosaurs or
directly below deinonychosaurs.

Mickey Mortimer