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Re: avian flight



> I also think that since
> the manus claws of early flyers such as Archaeopteryx occupied the same
> position on the wing and were approximately the same size as the alula of
> later flyers, the manus claws probably functioned aerodynamically much the
> same way as the alula.  It is very possible that the alula was not the
> evolutionary flight innovation some think it was, but rather was an
> exaptation of feathers that developed as the alular digit and the manus
> claws became reduced.   It's interesting to note that bats and pterosaurs
> also have/had leading edge protuberances in approximately the same leading
> edge location.  My bet is that they also probably function(ed)
> aerodynamically much the way manus claws did in early feathered flyers and
> as the alula has since the early Cretaceous.

Claws have completely inept shapes for this function, I'd say. And claws of
noticeable size coexisted with alulae in early ornithothoracines such as
*Sinornis*. Because pterosaurs did not have alulae, they had to taper their
wings extremely -- that's why pterosaurs have so extremely long wings for
their sizes.

My Humble Opinion: Confuciusornithids were able to fly better than Archie
and to glide because they lacked a long tail, but they had quite some
difficulties in slow flight and in manoeuvering because they had no alula.
In turn, their wing feathers were quite long (though not pterosaur-style).
Could be testable.