Re: Did dinosaur wings evolve for breeding display?/Longisquama

[Mike Habib <habib@jhmi.edu>]

David Peters wrote:

> Never forget Dial's studies with young birds with small wings.

The wings of juvenile chukars using WAIR are still larger than the  
forelimbs of Longisquama.  There are a host of other reasons that  
Longisquama would not be a good WAIR candidate, as well.  There is  
very little real evidence for even partial volancy in Longisquama at  
this time, but that does not mean it cannot have volant relatives.

> Also the previews to a new Disney movie, Earth, show a duckling  
> 'parachuting' to the leaf litter. Wing length is not as important as  
> you imply.

Wood ducks don't really parachute, so much as simply fall.  Their  
terminal velocity is quite low, and they fall onto leaf litter, so  
there is little need to speed reduction.  The falling ducklings do  
wave the forelimbs, and maybe produce some useful drag that way, but  
it is more likely that this is a reflex action related to an attempt  
to keep balance.

> Especially when you consider Longi's cousin: Sharovipteryx. Don't  
> follow your preconconceptions. Follow the fossils. Flapping doesn't  
> necessarily mean flying, either. Birds flap long before they fly  
> ontogenetically.

Yes, but for most species this is probably primarily a method of  
exercising the wings (which, in part, helps to stimulate strengthening  
of the forelimb skeleton).

Cheers,

--Mike


Michael Habib, M.S.
PhD. Candidate
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205
(443) 280-0181
habib@jhmi.edu