Coelophysoid-Protoavis connection?

["Waylon Rowley" <hot__male60@hotmail.com>]

I've read some posts on the list about the possible relationship between 
Protoavis and the Troodontidae. Currie says that the braincase and middle 
ear appear remarkably alike for animals separated by such a very long time. 
In The Dinosauria (Weishampel et. al. 1990, page 156), the tympanic cavity 
of the coelophysoid braincase is described as "....deeply recessed beneath 
the paroccipital process and is divided into a separate rostral and caudal 
chamber by a delicate oblique septum...." in the same work (page 262), the 
middle ear of Troodon formosus is also described as recessed beneath the 
paroccipital process and subdivided by a ridge. In The Complete Dinosaur 
(Farlow & Brett-Surmam 1997, page 231) 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. To me, it looks like a juvenile. 
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.
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