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Re: Hone and Benton 2007 (their second paper)
This reminds me of another question I had. (Keep in mind that I'm not
very knowledgeable about pterosaur aerodynamics, so bear with me...)
Certain pterosaurs (e.g., _Dimorphodon_) appear to have grasping
adaptations in the feet, including similar phalangeal proportions to
arboreal birds (Clark et al., 1998). So it's been suggested that
these pterosaurs were capable of climbing. If true, how would a
pterosaur launch itself from a tree? Having both grasping manual and
pedal claws would allow the pterosaur to grip the tree with all four
limbs, but how would it launch itself into the air?
Being in a tree actually makes launching quite easy, since the animal
can use a gravity-assisted launch. Essentially, an arboreal pterosaur
could simply drop off the tree and then start flapping. It would hit
flight speed quite rapidly using gravity-assisted launch, so the animal
need not fall very far. Arboreal birds use gravity assisted launches,
as do cliff-dwellers like tropicbirds. Arboreal birds do not require
gravity assistance, while tropicbirds (and frigatebirds) often do.
However, in both cases, the vertical descent prior to reaching cruising
speed is quite short. You can see it if you look for it, however.
Like arboreal birds, a tree-dwelling pterosaur would not require a
gravity assisted launch, but it saves energy if you happen to be at a
high point already.
If a pterosaur were launching from a tree (be it a trunk or a branch),
it could either use gravity-assistance, or a leaping launch (just as
from the ground for a branch launch; there would be a twist after the
initial leap involved for trunk launching). More than likely, arboreal
pterosaurs would use a combination of both gravity assistance and
leaping (which is what arboreal birds tend to do, especially larger
I hope that helps; definitely an excellent question.