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re:pteros have lift-off

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