Re: Byronosaurus jaffei

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

I'll finish up the Byronosaurus answers.....

Øyvind M. Padron wrote-

> From this picture it looks like Byronosaurus had a _VERY_ long and slender
> snout, compared to Saurornithoides. So i wonder, is this foto taken from a
> perspective that mischapes the specimen, or was it like this? What is
known
> of the skull structure, from what's hidden beneath the sandstone?
> Is there a reconstruction of the actual skull elements, besides this
photo?

The snout is really that long and slender.  I don't think there is anything
else "behind the sandstone", rather, the unseen portions of the skull were
broken off.  The braincase was preserved separately.

Fam Jansma wrote-

> Another thing regarding Byronosaurus and Troodontids in general: do they
and
> Alvarezsaurids contain any characters in common?

Indeed they do- lots of small teeth with basal constrictions, much more
numerous in dentary; no interdental plates; reduced anteroventral nasal
process; no squamosal-quadratojugal contact; a caudal tympanic recess that
opens into the columnar recess; carotid processes in mid-cervicals; reduced
cervical epipophyses; dorsal neural spine tables; short distal caudal
prezygopophyses; dorsal margins of ilia medially inclined to contact sacral
neural spines; fibula with tubercle for M. iliofibularis directed laterally
to caudally.
Probably why they often came out as successive sister groups to
eumaniraptorans in my old analyses.

Mickey Mortimer