[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Question: Why did birds lose their teeth?



Richard W. Travsky <rtravsky@uwyo.edu> wrote:

>> So the sequence is -- optimization of the wing reduces  wing claws
>> (and the need to climb) -- and the lack of wing claws reduces the
>
>
> So the inference here is that wing claws are indicative of less flying
> in the lifestyle? Which in turn might implies more time spent on the ground
> and/or in climbing.


One difficulty with this hypothesis is that a functional alula
('bastard wing') first appeared in birds in which the alular digit was
still quite long, and was tipped by a sharp (and presumably fully
functional) claw.  The presence of an alula implies fairly good flight
abilities.  So there is no evidence that wing-claws are indicative of
poor flight abilities or an aversion to flying.


However, it's not immediately clear what the function of wing-claws
actually was.  A function in climbing trees seems intuitively
attractive, especially in basal birds that preferred not to (or were
unable to) execute a ground-level take-off.  I'm not wholly convinced
that climbing was the raison d'etre for the retention of wing-claws in
many Mesozoic birds.






Cheers

Tim