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Re: Third claw for climbing was Re: Pro(to)avis



On 9/19/05, Tim Williams <twilliams_alpha@hotmail.com> wrote:
> 
> Now, we have _Microraptor_ and possibly _Pedopenna_, both
> of which are closer to the base of the Aves than either _Protarchaeopteryx_
> and _Caudipteryx_ (both of which are falling out as basal oviraptorosaurs).
> Microraptorans and _Pedopenna_ offer alternate ecomorphologies for
> pro-avians.  Then again, these four-winged gliders may have been an
> evolutionary dead-end and are just muddying the waters when it comes to
> reconstructing the origin of avian flight.

As Longrich (2003) noted, _Archaeopteryx_ also has long leg feathers,
albeit not as long as those of _Pedopenna_ and _Microraptor_. I
illustrated this in my last restoration:
http://dino.lm.com/images/display.php?id=3115

Taking into consideration that long leg feathers are unknown outside
of _Eumaniraptora_, it seems that the best assumption for now is that
the immediate ancestors of _Eumaniraptora_ had somewhat long leg
feathers, as in _Archaeopteryx_, but not the really long leg feathers
of the Liaoning deinonychosaurs. Of course, the sample size is pretty
durn small, so the "best" assumption is not necessarily that much
better than its competition....

—Mike Keesey