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Re: Relatively New Refs (long)



In a message dated 6/3/01 4:54:26 PM EST, david.marjanovic@gmx.at writes:

<< Pneumatic fossae and foramina are found on neural arches throughout
 Archosauria, and maybe beyond. >>

Well, now, isn't this nice? In my dino/archo phylogeny, skeletal pneumaticity 
is primitive to Dinosauria (not just "Saurischia"; secondarily lost in some 
prosauropods and all ornithischians, supporting close relationship between 
prosauropods and ornithischians) and is a feature consistent with the 
lifestyles of small, arboreal reptiles. Since such animals include the common 
ancestor of Archosauria, one would expect to find crocs with pneumaticized 
skeletons somewhere in their early fossil record (pneumaticization would be 
lost in aquatic lifestyles because it would make the skeleton too buoyant, 
which is likely why it didn't occur in later crocs).