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Re: Lemurs and Feathers



Dinogeorge@aol.com wrote:

Why not simply have the animal evolve a
rudimentary wing from a feathered forelimb that helps it to negotiate >in an
arboreal lifestyle, and then have these selfsame wings gradually >improve, until they're capable of sustained flight? These wings could >easily be exapted for brooding, underwater swimming, whatever you like, >at any stage of the scenario, as many times as you like.

I have to agree with George here. I think exaptation of feathers (from insulation --> aid in aerodynamic locomotion) is fine. But wings, even at their primordial (sifaka-like?) stage, probably served an aerodynamic function from start to finish.



David Marjanovic wrote:

[snip] except for a lack of arboreal adaptations in
theropods (such as mobile extremities and grasping feet);

This has come up before. Many features in small theropods pre-adapted them to the ability to climb trees - large hands; long, flexible fingers; inward-facing palms; trenchant claws... the retroverted pubis of dromaeosaurs, perhaps.


Remember, many modern animals (woodpeckers, tree shrews) can climb trees without the benefit of specialized scansorial claws. Heck, even goats and certain turtles can climb trees! (Thanks to Darren Naish for pointing out those last two examples to me.)


Tim

------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

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