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RE: the reason I asked about maniraptor limbs
Anthony Docimo wrote:
Based on information I gathered from the answers to my question earlier in
the week (last week?),
I made this sketch....
...and I'm wondering if such a difference between the wrist and ankle is
plausible, before I try making a final version of the tree dino.
(basically, for the hands, lift your hands up and clap once - the tree
dinos can't clap, but their palms do face each other.....the ankles,
however, have only the degrees of flexion as found in conventional
I thought this was true for all maniraptorans. The palms face inwards, but
the hindlimbs are held vertically and restricted to parasagittal movement.
Whether this combination is suitable for trunk-climbing is a totally
different question. I believe Chatterjee floated this idea (or a similar
idea) in his book - and additionally suggested that the stiff tail could be
used as a brace during climbing. But the idea of trunk-climbing
maniraptoran has been received with skepticism by some authors. For
example, here's what Padian (2003) wrote...
"Now, consider (as Paul and Chatterjee do) the hypothesis that flight
evolved in the trees, which requires these animals to climb trees. As Paul
points out, this is no problem for most animals if they have prehensile
hands or sharp claws. (However, it?s not this simple either. Goats can
climb trees by hooking their hoofed ??hands?? over branches, but they
couldn?t scale a naked tree trunk: there?s a difference between ladderlike
branch climbing and scansorial trunkscaling.) But the geometry of the body,
the features of the hands and feet, and especially the musculature and
kinematics of the limbsmust be considered. Chatterjee (1997) provided
diagrams of protobirds and early birds climbing trunks to show a possible
range of motion required, but he did not analyze the musculature to see if
it was consistent with and capable of these motions. Nor did he analyze
whether a forelimb whose major function is protraction, retraction, and
rotation (in flight) can also effectively supinate, adduct, and retract in
that position to achieve climbing "
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