re: the bipedal ptero-challenge

[DinoBoyGraphics@aol.com]

Dave,
     I'll try to get a better character list later (I have to be in class in 20 
minutes)

but 1) pterosaurs can't move bipedally like dinosaurs because they a) don't 
have their center of gravity in the right place for a horizontal posture,  b) 
fail to enlarge their illia anteroposteriorly like theropods do.

2) they don't show the adaptatins to upright bipedalism seen in hominids, 
especially the double curve in the sacral series.

I'm not indicating that all forms of bipedal locomotion was barred to them, but 
they don't appear to be specialized for it.  Of course during take off  they'd 
have to be bipedal for a short period, and I suspect that the ones that need to 
run for takeoff did so much like chinese water dragons (well, with wings of 
course).  But I don't see them foraging, etc. bipedally, though I wouldn't rule 
out the possibility of specialization in come forms, though none that I've seen 
particularly impress me in the biped department.

P.S.  There are quadrepedal ptero tracks all over central Wyoming.  They are ot 
rare, often making up the majority of the alcova-limestone ichnofauna.

Scott