Re: Pterosaur.net

[Mike Habib <habib@jhmi.edu>]

On Jan 14, 2010, at 11:42 AM, David Peters wrote:

> "The additional membranes (especially the front one) controlled by a  
> special bone called the pteroid would have helped with steering."  
> The pteroid was inboard and would not have been such a great  
> steering aid.

Because depression of the pteroid (and hence the propatagium) changes  
entry angle of the inboard wing, the pteroid would be a very good  
"steering aid" - flying taxa turn by altering the fluid force  
production between the two wings, such that they differ, which forces  
a roll and therefore a turn.  A little change in entry angle goes a  
long way, so the propatagial position is, in fact, a factor in  
maneuverability.

Cheers,

--Mike


Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181