Am 27.10.2011 10:30, schrieb Don Ohmes:
I am agnostic on the limits on upstroke amplitude in basal birds due to limited data and skills -- I am just pointing out that if they were severely limited in the manner that I have read is ascribed to Arch., then a path to powered flight that did not initially exploit gravity as the primary energy source rather than muscle power is not clear -- at least to me.
What about this scenario? http://www.dinosauria.com/jdp/archie/feather.htm
> Nevertheless, it is possible that these gliders might have used > simple flapping motions in order to gain height or added forward > momentum during the glide. Yes. Actually, I think that is a safe assumption, unless they were all dead-enders -- and even then...
What do you mean by "dead-enders"?