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Re: Deinonychus claw use and origin of flapping
On Fri, Dec 16th, 2011 at 12:02 PM, Tim Williams <tijawi@gmail.com> wrote:
> So the question becomes: Were the changes to the distal limb elements
> (= the putative incipient scansorial/arboreal characters) adequate to
> allow theropods to climb trunks or grasp branches, given the
> constraints imposed by the rest of the body?
That assumes that arboriality was practiced by any theropods (avian or
otherwise) before
advanced flight capabilities were available. Early avians could just as easily
have been using their
limited climbing skills to allow them to nest on cliff faces, and not be
utilising trees at all. There are
a lot more things in the world to climb than vertical tree trunks.
Living near cliffs would be ideal for a creature that could sort-of fly, and
for whom terrestrial
locomotion was still important. They could run from danger on the ground when
it was a sufficiently
successful response, and if really pressed could launch themselves off a cliff
edge in order to
escape predation. The same may have been true for pursuing prey - chase prey
about on the
ground most of the time like their ancestors did, and if they proved too adept
at avoiding capture
then attempt to heard them off a cliff. The non-volant prey would most likely
fall to its death, while
the sort-of volant predator could glide/parachute down in relative safety to
dine on the pre-
tenderised carcass.
--
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Dann Pigdon
Spatial Data Analyst Australian Dinosaurs
Melbourne, Australia http://home.alphalink.com.au/~dannj
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