Re: Gliders to Fliers? (Was Re: Ruben Strikes Back)

[NJPharris@aol.com]

In a message dated 9/24/99 5:22:08 PM Pacific Daylight Time, 
Dinogeorge@aol.com writes:

> I consider it just as likely that dinobirds were originally quadrupedal 
>  semi-sprawlers, and that once the forelimbs had become too winglike to be 
>  used for walking, they would no longer evolve quadrupedal forms.

Yes, but flying animals have evolved from quadrupedal, branch-hugging forms 
before (bats, likely pterosaurs), and in those cases the wings evolve in such 
a way that they never are "too winglike to be used for walking".

The total decoupling of fore- and hindlimbs in avian locomotion implies to me 
that the two sets were already completely decoupled before there was any 
development of the arm towards a wing condition (i.e. that pre-flying birds, 
whenever they might have lived, were already completely bipedal).

--Nick P.