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Re: Screaming dromaeosaur biplane killers of the air

"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.


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