Re: pterosaurs in trees:

[NJPharris@aol.com]

In a message dated 97-06-18 18:39:20 EDT, longrich@phoenix.Princeton.EDU
(Nick Longrich) writes:

>       Was the wing really so long and narrow? Why not attach it to digit
>  #5? that would greatly increase your wing surface. I am not arguing all
>  rhamphorhynchs did this, but some could have and it would have created a
>  much broader wing.

Well, there is evidence that some rhamphorhynchs (e.g. _Sordes_) did have the
wing membrane attached to the ankle or thereabouts.  Others, including
_Rhamphorhynchus_ itself, had the membrane attached higher up the leg.  These
are, IMHO, probably adaptations for different habitat types.

>  it has been demonstrated that gliding is an effective and efficient
>  way to move through the forest (and by Mother Nature, not just by math),
>  and once you have developed wings, you need only add thrust: the
>  downstroke- to stay aloft longer and longer. 

This may be true in theory, but *nowhere*, either in the fossil record or in
the range of living animals, do we have direct evidence of a gliding animal
taking up powered flight.  Even the very earliest examples of pterosaurs,
bats, and, I believe, birds were fully powered fliers.  There are gliding
marsupials, gliding rodents, gliding primate relatives, gliding frogs,
gliding lizards, gliding fish, and even gliding snakes; but none of these
groups has made the transition to powered flight.  This suggests to me that
gliding and powered flight are two separate and (at least largely)
independent adaptations.

NP