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Re: poling dangers
I think you are having issues with the sticky problem of aquaeous
drag. If I'm reading your right, in your vision of the situation, I
sense a need to elevate the wings quickly, which would be difficult
under deep water during poling...
That is part of the problem, yes, but there is also the problem of the
forelimbs being unable to push against a substrate to produce launch
forces (see below).
1) As the head rises above the surface, the eyes, set far back on the
skull, break water, sense danger then things start moving. First,
everything flexes in panic. Flexion of the humerus brings the already
folded wing forward to the surface in a configuration the pterosaur
might also use to rest on dry ground...Momentarily freed from the
water, the wings snap laterally and start flapping, but only employing
the top half of
the beat cycle in order to avoid reentering the water.
I am impressed that you worked that out off-the-cuff so well, but I am
somewhat unconvinced that Quetzalcoatlus could launch in that manner.
Jim already responded to the scenario better than I could, so I'll just
add that simply freeing the limbs from the water is probably
insufficient. In that scenario, the Quetz. has to start flapping
frantically to get up to speed. Not only are the wings going to hit
the water during the first stroke cycle, but I would also expect that
the launch would be very slow indeed (and it brings up the question of
whether Quetz. could launch without pushing off the ground at all). A
Quetz. launch would be darn fast if it could catapault from a
substrate, but probably pathetically slow if try to "hovercraft" its
way into the air.