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RE: Yet more on pterosaur quad arm posture
> It counts as climbing.
Hopping from branch to branch (and repeatedly falling off) counts as climbing?
...Uh, sorry. This might be a linguistic misunderstanding. In English you
"climb" stairs, and you can "climb" a mountain by just walking up instead of
pulling yourself up a rock face; German has a more specialized word, and that's
what I had in mind all this time.
> Again, for perching adaptations to evolve, there was a population of animals
> that went into elevated perches WITHOUT such adaptations, and that provided
> the selection pressure for them to evolve. Were basal paravians all doing
> that, and did it take until, say the Sapeornis node in Avialae for the
> arboreal adaptations to arise?
Well, if they were all doing that for 40 million years till that node, I'd
expect some adaptations to arise earlier than that.
> The only other way it could have happened is if there were exaptations, such
> as gripping feet (Fowler et al. 2011), that allowed elevated perches and were
> later replaced by reversed halluces. This exaptation is reported for
> dromaeosaurs, which are also paravians.
And it makes plenty of sense. Indeed, the hallux already isn't perfectly
parallel to the 3rd toe in those dromaeosaurs -- all claw tips converge during
> And, when we ask what good the intermediate stages of flapping flight would
> be, a valid answer is "to get 1 meter off the ground into a low roost",
> because living basal birds (tinamous, galliforms, anatids) still share the
> character of roosting this way.
Very good point.