Re: pteros have lift-off

[David Peters <davidpeters@att.net>]

> 
> Consensus [on hindlimb leaping ancestors]?

Padian championed bipedal locomotion. Bennett followed von Huene who championed 
arboreal leaping and illustrated Eudimorphodon's hind limb in a leap. No one 
else I am aware of has broached the subject. If you choose dinos or 
Scleromochlus as sister taxa, you have long hindlimbs and short forelimbs. The 
same if you choose Cosesaurus and Sharovipteryx. No other taxa have been 
promoted seriously with matrices.

David Peters

> 
> If anyone were to find bipedal trackways, it would convince
> me that some 
> pterosaurs were bipedal.  So far, I don't think such
> trackways have been 
> found.  Note that all pterosaurs land bipedally, but they
> are unlikely to 
> remain in that mode for more than a couple of  hops and/or
> stutter steps.

Just Google 'Bipedal pterosaur' and maybe Michelson and you'll find some 
references. 
> 
>
> 
> >Final question: how much angle do you figure at the
> carpus to create  your 
> >Z fold in the forelimb?
> 
> It depends upon wind at the time of launch and weight of
> the animal at the 
> time of launch.  The carpal shear mechanism in the wing
> that I've been 
> manipulating disengages at an interior angle of about 80 -
> 85 degrees, and 
> I've been using a minimum interior angle of  about 90
> to about  95 degrees 
> (carpal shear is near its minimum during launch). 

Wow. That's a lot. Much more than I expected before disarticulation. But 
nowhere near what one would call a Z-fold.

> JimC