Re: Ornithodesmus (Was Re: CRETACEOUS STEGOSAURS)

["Simon M. Clabby" <dinowight@yahoo.co.uk>]

 --- Mickey Mortimer <Mickey_Mortimer111@msn.com>
wrote: > Simon M. Clabby wrote-
> 
> > >Current thought would have it as
> > > a troodontid, or
> > > dromaeosaurid, or some generic maniraptoran.
> >
> > Also, it shares features with coelophysids and
> > abelisaurids, amongst many others
> 
> The troodontid assignment was based on comparison to
> a dromaeosaurid sacrum.
> Which features does it share with ceratosaurs that
> aren't found in
> dromaeosaurs?
> 
Well, apart from the lack of dorsoventrally flattened 
transverse processes, I'm not sure about dromaeosaurs,
but the factors that attribute it to the Coelophysoids
and the abelisauroids are (and I quote from Martill
and Naish's excellent 'Dinosaurs of the Isle of
Wight') "...ankylosis of at least four sacrals, a
sacrum with six sacrals, and a neural spine
laminae...", and it's fenestral sacral plate is
reminiscent of coelophysoids.



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