Re: pteros have lift-off

[David Marjanovic <david.marjanovic@gmx.at>]

----- Original Message -----
From: "David Peters" <davidpeters@att.net>
Sent: Sunday, January 11, 2009 12:40 PM

> Using the same criteria and model, I have a problem seeing Istiodactylus 
> leaping. Pectoral girdle smaller than half the size and not fused. Humerii 
> huge, okay. Massive antebrachium, okay. Wing finger, nearly three times 
> longer relative to torso. Big problem. It has to leap three times higher 
> to follow the same wing opening trajectory, whatever the lateral angle, on 
> forelimbs no larger than Q. and hindlimbs half the length relative to 
> torso. So comparing apples to apples, Istio needs a 3x larger effort on 
> weaker equipment than Quetz.

You seem to think that the leap must result in fully extended vertical wings 
that don't touch the ground. Is that the case? Could it have ended with 
everything _except the wing finger_ fully extended and vertical, then an 
upstroke, and only then a full downstroke during which the entire wing is 
extended?

This would of course require that the pterosaur continued to move upwards 
during this first upstroke, powered by leftover inertia from the leap. 
Whether the power for that was available is testable.