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

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).



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