re:pteros have lift-off

[David Peters <davidpeters@att.net>]

Tim W. wrote: >>But the earliest known pterosaurs are highly derived
morphologically, and in the absence of intermediate forms it is not  
possible to
be too confident regarding the behavior(s) of pre-flight pterosaurs (or
pterosauromorphs).  <<

Highly derived? No intermediate forms? Intermediate between what and  
pterosaurs?

Just find a diapsid taxon or two (if parts are missing) with a  
displaced naris, an antorbital fenestra, multi-cusped (not serrated)  
teeth, a keeled sternal complex (interclavicle+clavicle+sternum), an  
attenuated tail without descending chevrons but with elongated  
centra, a proximal deltopectoral crest, an appressed radius/ulna,  
metacarpals that elongate laterally but III equals IV, manual digits  
that elongate laterally but V is very short, an elongated ilium, a  
fused pubis/ischium, a longer tibia than femur, an attenuated fibula,  
a simple hinge ankle-joint, metatarsals that elongate laterally,  
pedal digits that elongate laterally, a pedal digit V with an  
elongated proximal phalanx and fiber-supported dermal membranes  
trailing any of the limbs. Shouldn't be too hard. I can think of a  
few just off the top of my head. I'm sure you can too.

And getting back to that arboreal theory, which theropods prior to  
Archaeopteryx and kin had long forelimbs?

David Peters
davidpeters@att.net