Re: Coelophysoid-Protoavis connection?

["Rob Gay" <rob_redwing@hotmail.com>]

Waylon Rowley wrote:
> the skull of Protoavis is partially reconstructed. The orbits are huge and 
> the bones don't appear to have interdigitated or have been well-sutured.<
This may be true. However, if this is so, it may just be a juvenile 
_Protoavis_, and not a coelophysoid. Lots of other theropods have large 
orbits (_Troodon_, for one example, as you mention).

> So, is it possible that Protoavis is a baby coelophysoid with a 
> non-ossified jugal-postorbital bar and a middle ear convergent with those 
> of the Troodontidae? It seems like a more parsimonious explanation for such
an ancient animal.<
I don't view this as likely. With the huge ammount of specimens known from 
_Coelophysis_, including many infants and juveniles, it would seem unlikely 
that Chaterjee would mistake a coelophysoid skull for something else, even a 
juvenile. I don't have his Paleontogrpahica paper (but it is on order from 
ILL!!) yet, so I can't comment further on this diagnosis. But, as I said, 
it's unlikely that a juvenile coelophysoid skull and an avian skull (even a 
basal one) could be easily confused. Though you are right about 
coelophysoids (at least _Coelophysis_) having some things functionaly 
similar to _Troodon_.
Peace,
Rob

Student of Geology
Northern Arizona University
P.O. Box 20840
Flagstaff, Az. 86011
AIM: TarryAGoat
"A _Coelophysis_ with feathers?"

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