Re: LARGE PTEROSAURS OF EARLY CRETACEOUS MARYLAND

["Ray Stanford" <dinotracker@earthlink.net>]

    Jim Cunningham said of the pterosaur prints shown to him on my way to
Texas in May, "Ray has shown me these prints.  There is no doubt in my mind
that they are pterosaurian.  I thought Kevin's argument magnificent (and
passionate), but I think Ray's prints might persuade him.  Personally, I
found them as convincing as Crayssac."

    I want to thank Jim for that very nice and unsolicited input.  It is
deeply appreciated, yet I really wonder how much of an open mind Kevin
Padian has, despite his recent cognitive progress regarding pterosaur
terrestrial locomotion, considering his track record (pun intended) on
tracks attributed to pterosaurs, over the past years.  I wonder whether
there might be a conscious or unconscious tendency, now, to protect himself
from past statements passionately made, attributing a non-pterosaurian
origin to pteraichnid footprints?  Or, do Padian's scientific qualifications
and reputation suggest he is above such a human tendency?

    If any one of you could provide me with a copy of Padian's paper (if
there is such a thing available at this point) delivered at the recent
pterosaur conference in France, it would be adult-sauropod-track-size
appreciated.

    I read with interest Kevin's transmission to this list recently,
following that of Unwin, but at least in the abbreviated presentation of his
argument to this list, he seemed to be overlooking some important insight
into the possibly significant kinematics of pterosaur manus track formation,
plus other possibly meaningful things.  Pterosaur manus implantation into a
substrate is not like fingerprinting at a police station, yet Padian seems
to deal with it in a rather simplistic way.

    Why is such an analysis incomplete or inadequate?  For example, the
transfer effect (upon the motion of manus components) of angular momentum
(resultant rebound) from the step-attendant arcing motion of the extremity
of the very long, upward extending digit four 'wing finger' (plus its
attached wing membrane) should probably be taken into account and analyzed,
instead of just looking at bones of a pterosaur manus and deciding how the
track should look.

    One might also consider what kind of motion each manual digit might have
had during removal, and, for example, whether that motion occurred to
accommodate simple forward progression or, in rare cases, a launch into the
air (of which I think there may be some examples in the Maryland
collection).  The latter might even prove instructive toward understanding
pterosaur launch mechanics, as might the launch-situation pes (back foot)
imprint.

    Oh the mysteries of pterosaurs!

    Ray Stanford

"You know my method.  It is founded upon the observance of trifles." --
Sherlock Holmes in The Boscombe Valley Mystery

----- Original Message -----
From: "James R. Cunningham" <jrccea@bellsouth.net>
To: <fabdalla@box1.tin.it>; <dinosaur@usc.edu>
Sent: Friday, October 05, 2001 5:58 AM
Subject: Re: LARGE PTEROSAURS OF EARLY CRETACEOUS MARYLAND


...