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----- Original Message -----
From: "Robert J. Schenck" <nygdan@yahoo.com>
Sent: Sunday, September 24, 2006 7:02 PM

Mr. Longrich states:
"I found that the feather structure and
arrangement indicated that they were used as
lift-generating winglets, and calculated that
these structures could have significantly
decreased both the stall speed and turning radius
of the bird"

It seems that their being wings stands or falls
upon that statement alone.

...and Archie's well-known inability to spread its legs.

Mr. Marjanovic:
"Bats and pterosaurs don't have such a thing at
all. A flexible furcula clearly helps, but I can't
see why it should be necessary."

I think that the arguement being made here is
that its parsimony in the phylogentics of the
evolution of birds requires that such a structre
shoudl be involved in the evolution of bird
flight, rather than that such a structure is
required for flight at all.  Indeed, if its not
present in bats and ptersosaurs and other flying
creatures, doesn't that argue for it being a
specific characteristic and related to flight
that pops up in the bird line? Rather than that
birds developed flight, and then later developed
this and other features?

I don't think so. Bats cannot afford evolving a furcula (the joint between wing and body is the joint between clavicle and sternum in bats!), and the pterosaurs seem to have started out lacking clavicles in the first place, so we don't know if they'd benefit from a flexible furcula. Insects are not comparable, and there are no known "other flying creatures". Within birds, it is certainly an adaptation to flight, but do you really think *Confuciusornis* or *Sapeornis* could have been anything but fliers? It makes flight easier, but I don't think it makes flight possible in the first place.

Is there are variation of WAIR that invovles the
leg feathers/leg wing?


If WAIR is the activity
that most leads to flight in the evolution of
birds, it requires that the legs be powerfully
developed and devoted to running no?


And then there was the case of the 4-legged

That's something completely different -- the legs are duplicated, while nothing happens to the wings.