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Re: Science feather strength debate



Augusto Haro <augustoharo@gmail.com> wrote:


> After going to read Scott's abstract, it seems there are remiges, but
> very small and only on the distal half of the humerus. This looks to
> me like proof on his part.


I'm ashamed to say I don't have the abstract - could you or Scott or
somebody post it here?  This might help to clear up your statement "
it seems there are remiges, but very small and only on the distal half
of the humerus".  If these remiges are on the humerus... then aren't
they tertials?


As an aside, this is as good a place as any to point out that the
terms "tertial" and "tertiary" have a rocky history in ornithology.
The term "tertial" has been used (and is still used) for the modified
proximal (innermost) secondaries that cover the bases of the primaries
when the wing is folded.  As secondaries, these "tertials" are
attached to the ulna, including the olecranon process.  But the term
"tertial" or "tertiary" is also applied to those feathers positioned
on the humerus, which do not belong to the same row as the
secondaries.  These "tertials" or "tertiaries" are attached to tissue
superficial to the humerus, and are sometimes called "humerals" in
order to avoid confusion with the other use of the term "tertial" for
modified secondaries.


What we are debating here is if _Archaeopteryx_ had remiges along the
humerus, or if the remiges were attached only to the ulna and manus.
If the latter, then these distal remiges might have been used not for
gliding efficiency, but for control of body position during brief
descents.  This is the central thesis of the "Pouncing Proavis" model,
which proposes that the ancestors of birds used proto-wings for
aerodynamic control during ambush attacks that targeted terrestrial
prey, launched from rocks, ledges, or small trees.  This control was
initially drag-based, but became more lift-based as the forelimb
feathers became larger, stronger, and asymmetrical.



Cheers

Tim