Re: STRANGE THEROPOD SKULLS

["Matthew Troutman" <m_troutman@hotmail.com>]

>*Cryolophosaurus* is so early in the fossil record, possibly the first 
>true carnosaur (Eucarnosauria? with Carnosauria including that group 
and 
>all other basal tetanurines {megalosaurs, torvosaurs, abelisaurs, and 
>*Eustreptospondylus*} excluding Coelurosauria and spinosaurs and 
>*Bagaraatan*---however he fits in, and I've yet to see a skeleton or 
>single bone of this creature)

     While I agree that Crylophosaurus is a carnosaur, I think there is 
more than a little evidence for a "higher" position. Sereno et.al. 1996 
argued for a position in the Allosauroidea. This position is based on 
nasal participation in the antorbital fossa, basipterygoid process very 
short, basioccipital excluded from the basal tubera, articular with 
pendant medial process, and surangular twice maximum depth of angular. I 
agree with their postion in this matter. 
      Abelisaurs may belong the Ceratosauria in the taxon 
Neoceratosauria as Novas speculated.  
      Spinosaurs are related to Torvosauridae and Afrovenator in the 
Torvosauroidea according to Sereno et.al.  More will be published on 
this when Sereno publishes his newest findings from Morocco. 


><I still find it hard to believe that the jugal does project so far 
>dorsally as to suture with the squamosal and therefore divide the 
>laterotemporal fenestra into two - this is utterly unique if true. 

    Based on the partial picture Hammer and Hickerson show I think it is 
true.

   
     >>snip<<



>How about this: *Baryonyx's* pelvis shows remarkable similarity to the 
>referred pelvis of *Megalosaurus* (OUM, no number given) as seen in 
_The 
>Dinosauria_ and _Dinosaurs: the Encyclopedia_. And don't get me started 
>about *Afrovenator* and *Eustreptospoindylus*---though Afro and 
>sinraptorids is also very interesting.... Hmm. Would *Piatnitzkysaurus* 
>and *Monolophosaurus* and *Yangchuanosaurus* sound interesting as a 
>group: look at their pelves (especially the ischia).

     The pelvis may not be a great diagnostic feature in theropods. 
Baryonyx and Megalosaurus may have some relation but you cannot base it 
on some general similiarities. Function-related parts of the body can 
look extremely similiar in unrelated animals with similiar lifestyles. 
Afrovenator and Eustreptospondylus may have some relation but 
Afrovenator and sinraptorids have relation. Sinraptorids and 
carcharodontosaurs is more likely. Piatnitzkysaurus may be 
related to Monolophosaurus and Yangchuanosaurus if it is a allosaur and 
the latter two are too. Bakker proposed there is a clade of theropods, 
the monolophosaurs, but that was at the SVP conference and I didn't hear 
the exact details. Somebody fill me in?

  WMattTroutman
     



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