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Re: Pterosaur help and Rahonavis; sickle-claws




Silvio Renesto wrote:

It appeared in the literature that [Megalancosaurus] had a birdlike >semilunate carpal. This was simply due to the hanging hypothesis of >bird relationships.

An appropriate choice of words. The evolutionary model which held that birds evolved from _Megalancosaurus_ deserves to be "hanging". Perhaps drawn and quartered as well.



David Marjanovic wrote:

Unlikely IMHO. The function of such a parasagittal climbing device could be
fulfilled much better by a pamprodactyl foot (all 4 toes point forwards),
which exists in mouse birds = Coliiformes, while a single enlarged claw on
II, III or IV which functions as a climbing aid does not exist in any >bird AFAIK.

A pamprodactyl foot seems to be a little drastic, if all you want to do is climb up a trunk. The sickle-claw of dromaeosaurids *might* have been co-opted for such a use. There's certainly more than one way to climb a tree. On that note, you may find this post of particular interest:


http://www.cmnh.org/fun/dinosaur-archive/2001Oct/msg00185.html



Tim

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