Re: Conway's Velociraptor (and pterosaurs)

["Jaime Headden" <ja_headden@qilong.8m.com>]

Jim Cunningham (jrccea@bellsouth.net) wrote [replying to Luc Bailly 
(aspidel@wanadoo.be)]:

<I like your positioning of the foot a bit better than John's, though I think 
you both are spreading the proximal tarsals too much.
My own impression of the flight positioning of the foot reminds me more of the 
positioning of a swimming beaver's hind foot.... so
that the camberline has a slightly negative aoa for zero lift.  I think of the 
flight function of the foot as a trim servo.>

  I am curious about the foot position in these animals for other reasons, 
especially the functional use of the fifth toe in
"rhamphorhynchoids" versus pterodactyloids; if there was a functionally 
adaptive use to preserve the function of this toe in
rhamphorhynchoids, why was this lost in pterodactyloids if the foot/leg useage 
in the uropatagium was the same? It would seem the
use of the toe would have a distinctly advantageous usage that was lost in 
pterodactyloids, but that the pterodactyloids retained
some advantage by selectively repressing this feature early in their evolution. 
If so, this seems to suggest that their relative
"hind wing" function, if present, was different. However, in the art of both 
John Conway (john@pterus.net) and Luc Aspidel, these
legs are drawn in the same position, knee forward and foot volarly-ventral 
(pads down) (which I don't get anyway, given the
mesotarsal ankle and un-twisted tibia). I am curious why this is offered, or if 
the same leg position is provided for pterosaurs
generally?

  Cheers,

  Jaime A. Headden

  Little steps are often the hardest to take. We are too used to making leaps 
in the face of adversity, that a simple skip is so
hard to do.  We should all learn to walk soft, walk small, see the world around 
us rather than zoom by it.

  "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)