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Re: dino-lice



Vivian Allen <mrvivianallen@googlemail.com> wrote:

> I think we can agree Jason has made Shuuvia and
> Mononykus exerting large forces with their pectoral limbs sound pretty
> difficult.


Speaking for myself, I don't agree at all.  I'm not doubting the
efficacy of Senter's biomechanical work, which posited that the
forelimbs of _Mononykus_ are suited for scratch-digging or
hook-and-pull movements.  What I'm skeptical about is whether
_Mononykus_ (or any other alvarezsaur) deployed the forelimbs as part
of a specialized ant- or termite-eating ecology - specifically,
targeting insect nests or insect-infested wood.  It doesn't mesh with
the remaining proportions of the alvarezsaur postcranium; it requires
a highly cursorial animal with an elevated metabolism to subsist on a
low-calorific diet; and the anteater/vermilinguan analogy is not
especially compelling considering that these extant mammals have long
forelimbs capable of a wide range of motions.


I agree with GSP that the pectoral musculature is way over-the-top for
just an ornamental structure.  Plus, the manus retained a single large
claw - what was it there for if the forelimb was used only for
display?  There is no indication of atrophy of the alvarezsaur
forelimb - just heavy-duty truncation.




Cheers

Tim