RE: flight

[Phillip Bigelow <n8010095@henson.cc.wwu.edu>]

>Bill Barbour writes:
>And what is the physiological evidence that archaeopteryx was a climber? Is
>it definitive or speculative in nature?
>I think hard evidence one way or the other is sketchy at best. No doubt, that
>is what inspires such debate. :-)
>As always, I appreciate any comments.

>Bill Barbour
>Assistant Education Curator
>Natural Science Center of Greensboro

 If you happened to watch Larry Martin describe his Archaeopteryx on the
1990 Nova telecast, there are some things to note about Martin's
reconstruction ("The Case of the Flying Dinosaur").
  Martin has his Archaeopteryx in a near primate-like stance.  According to
Martin, this would give the protobird a center of gravity closer to the tree
trunk, and would facilitate climbing.   However, if you look closely at the
tail vertebrae on his mount, Martin has the tail curling backward and
upward.  I am just guessing here, but I presume that the tail orientation is
"artistic license" on Martin's part.  Still, it bothers me for the
following reasons:  In order for Martin to mount Archaeopteryx standing on
the ground, the primate-like stance would cause the tail to grind into the
ground (probably rather painfully). This would also damage tail feathers. 
Did Dr. Martin curl the tail backward on his Archaeopteryx  
because it would dig into the ground?  If so, maybe the nearly vertical
orientation of the vertebral column is wrong.  Dr. David Norman once wrote
about how 19th Century workers literally had to _break_ the tail vertebrae
on Iguanodon so that the tail will drape nicely on the museum floor
in the upright stance they had Iguanodon in.  The correct orientation for an
Iguanodon in locomotion is with the spine and tail in a near-horizonal
position.
  Martin wouldn't have to curl the tail out of the way if he had mounted his
Archaeopteryx in the typical theropod stance (vert. column nearly parallel
to the ground).  The other problem I have with the curled tail is that,
there would be no physiological reason to curl the tail in the first place.
The caudal vertebrae are not designed to be prehensile on Archaeopteryx.
  This of course becomes a moot point if the articulation surfaces on the
bones forced Martin to reconstruct the skeleton the way he did.  Dr. Martin
challenged other researchers to use his Archaeopteryx casts and try to mount
the protobird in another posture.  That was in 1990.  Has anyone taken him
up on that challenge?