Re: FOUR, THREE, TWO, ONE . . . PTEROSAURS HAVE LIFT OFF!

[David Peters <davidpeters@att.net>]

Interested to find out what you mean.

I should have clarified saying, rather than 'vertical', 'at a high  
angle aligned in the parasagittal plane'. Pretty much the same with  
reference to wing folding, especially so in anterior and posterior  
views. Sure the metacarpus could be leaning aft or forward in lateral  
view. The point is, the wingfinger has to go from the vertical plane  
at launch and just afterwards (during the squash and stretch phases),  
to a series of oscillating planes averaging horizontal (aka flapping).

I hope your pterosaur doesn't attempt a leap with widespread (in  
anterior view) metacarpi!

David



On Jan 9, 2009, at 8:13 AM, jrc wrote:

> More later, gotta go pick up my grandson.
> David, both your statements below are wrong.
> Also, the duration of the push off varies among species, but that  
> plus the unfolding takes almost exactly the same length of time as  
> a flapping downstroke for the same animal.
> JimC
>
> Dave wrote:
> At manus lift off, the metacarpus would, of necessity, still be
> vertical, having just pushed off the earth like a airborne pole
> vault. A vertical metacarpus means the wing finger was still in the
> vertical plane,

David Peters
davidpeters@att.net