Re: Yet more on pterosaur quad arm posture

["David Marjanovic" <david.marjanovic@gmx.at>]

> We agree that animals that are not scansorial do roost in trees.

...if they can fly there. (WAIR probably counts, too.)

If they climb there instead -- if they do what practically no bird ever does 
today: start on the ground and climb into the crown --, they're scansorial: 
natural selection for climbing ability kicks in, and they evolve adaptations to 
climbing.

Lots of terrestrial or semiaquatic birds roost in trees _because_ they can do 
so without climbing.