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Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)



Archaeopteryx appears to be a bad climber, because of the lack of
wrist mobility, except for wing extension-flexion, apparent lack of
ankle mobility in senses different from extension-flexion, and also
for coxofemoral articulation. At the same time, it has curved claws,
suggestive of some climbing abilities. I think the origin of flight
might have to do with theropods being such bad climbers, as a feature
which enabled them to climb the better. Today, most birds do not need
to climb because they can fly from branch to branch.

Perhaps Archaeopteryx and other small Deynonychosauria used their
wings, and flapped on, in order to maintain equilibrium on the
branches of the trees, while walking bipedally. Probably they needed,
more than other climbers to account for equilibrium devices because
they were bipedal climbers. Perhaps, if as Evelyn says, WAIR is
correlated with short, rounded, wings, but it is possible even
Archaeopteryx may have used it at least in those moments when it was
about losing its balance (or needed to climb fastly for a short
distance).

Perhaps theropods were flapping even before parachuting, to maintain
balance in an environment where they were not so adapted to climb as
most animals. Even when parachuting, flapping, as weak as it might be,
would help at least changing direction of advance, or perhaps
accelerating a little the descent, to avoid, for example, to be
catched by a volant predator as a pterosaur (I don't know if there was
a Jura German ptero capable of taking an Archaeopteryx). However, I
don't know if this hypothesis of flapping-helping-parachuting is
aerodinamically possible.