re: Poling marks

["Jaime A. Headden" <qilongia@yahoo.com>]

David Peters (davidrpeters@earthlink.net) wrote:

<I don't argue that. I argue that, as in using a cane, the wide snowshow feet
don't sink as deep as the narrow cane-like fingers due to the area they cover.>

  I would like a test of this idea. It should be relatively easy to determine
the relative area of a pes print of the crayssac tracks to a manus print of the
same trackmaker and determine the relative area coverage, rather than argue it
as above. One can also build models of pterosaur hands and feet and make
walking experiments as with crutches, and see which sediments compress or do
not compress as easily under the same walking scenarios. One can presumably do
the former on a computer, and I think AutoCAD and some Photoshop plugins will
allow one to compare the digital area of pixels in a non-transparent part of a
gif file.

  I personally have no problem with swimming pterosaurs, and I personally have
no difficulty with floating animals overcoming their natural bouyancy somehow
to feed. Ducks, being the airfilled creatures they are, regularly sink
themselves (partially) to feed, as just a rather commonly-available example.
These birds do not, as far as I can tell, deflate or infill their bodies, nor
do they possess any relatively heavier bones than other birds that swim but do
not sink or "bob" for algae. Instead, ducks struggle to keep themselves
underwater by wing and foot action, so its not at all a passive submersion.

  Cheers,

Jaime A. Headden
http://bitestuff.blogspot.com/

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

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com