Re: pterosaurs in trees:

[Dinogeorge@aol.com]

In a message dated 97-06-20 22:52:15 EDT, NJPharris@aol.com writes:

<< 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. >>

You can also conclude, more directly and simply, that flying is a difficult
and fortuitous adaptation even for gliders.