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Re: Arms into wings



In a message dated 3/3/99 10:50:42 AM, Tim Williams tsg94001@uconnvm.uconn.edu
writes:

<< What good is half a wing, etc?  I'm not arguing against a
maniraptoran origin of birds - but for my own benefit what kind of changes
MAY have occurred in the design of the forelimb (especially externally -
i.e. feathers) between a non-flying basal "eumaniraptoran" and a flying
avian like _Archaeopteryx_?  There must have been a "not-quite-flying"
phase somehere in the middle, so what was the forelimb used for during this
stage? >>

Brooding. As Mark Orsen and I presented at Dinofest 98, the entire progression
from featherless flightless reptiles to feathered, flying birds, makes good
sense if the first reason for long feathers on the arms was to cover eggs and
babies. Then, your "not-quite-flying" condition equals a "well-adapted for
brooding a larger number or size of offspring" scenario. Aerodynamic feathers
come from the need for streamlining. No fossil evidence is paradoxical in this
progression -- i.e. caudipteryx makes sense, too.

Tom Hopp