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Re: "Flight theory has legs"
On Fri, Jul 11, 2003 at 09:24:11PM -0700, Jaime A. Headden scripsit:
> Previous analyses indicate that the use of both manual and pedal claws
> can be exapted to the same degree, as in colugos, squirrels and other
> terrestrial sciuromorph rodents, and bats,
This can't be extended to aviform dinosaurs, though; they don't have the
basic mammal tree-or-ground-hugging-splat posture.
> but that the size and claw shape in some bats show a greater use in
> one set than another for climbing (megachiropteran bats hang by the
> foot claws, whereas never contact the substrate with the manual
> pollecial claw) resulting in a shape dichotomy between the two. This
> seems to be a serious issue in play, and one that should be (or should
> have been) resolved prior to the extrapolation of the thrust of the
Until someone finds quadrepedal bird tracks, I think the
no-substrate-contact is a pefectly decent assumption.
I am also unable to come up with a hand-claw climbing scheme that
wouldn't involve the feet at all; the shoulder anatomy wouldn't let them
hang straight down from the hands.
firstname.lastname@example.org | Uton we hycgan hwaer we ham agen,
| ond thonne gedhencan he we thider cumen.
| -- The Seafarer, ll. 117-118.