Re: Screaming dromaeosaur biplane killers of the air

["Tim Williams" <twilliams_alpha@hotmail.com>]

"Philidor" <philidor11@snet.net> wrote;

> Are you sure that you want to include the 'use it or lose it' principle? 
> There goes retention of neutral mutations, among other problems.

Yes, I'm quite sure.  I don't think one can assert that the hindlimb 
feathers were 'neutral'; as Xu et al. (2003) note, enormous feathers 
sprouting from the lower hindlimb would have been an impediment to running.

BTW, it is difficult to prove that _Archaeopteryx_'s legs were unfeathered.  
What can be said is that the hindlimbs of _Archaeopteryx_ specimens lack the 
pennaceous feathers preserved along its distal forelimb and tail.  However, 
the trunk and upper arm of _Archaeopteryx_ specimens lack feathers, and 
their absence from these parts (and from the legs) may be a taphonomic 
artifact.  Or, it could be real.  However, some neornithine birds from the 
Messel lack humeral feathers, though more distal wing feathers are clearly 
present.  This is certainly an artifact.



Tim

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