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Re: the maniraptoran wrist




"Williams, Tim" wrote:

> There is an alternative hypothesis that the folding mechanism of the
> arms was designed to reduce rotational inertia during such predatory
> pursuits. (I've mentioned the paper on this list, but can't recall the
> auhors at the moment.)  As such, tucking the arms against the chest improved
> maneuverability - which might be regarded as useful to predators that relied
> on brief chases to run down prey.  The maniraptoran forelimbs were deployed
> only when the prey was within reach - but during the chase the long, gangly
> forelimbs were kept out of the way.

Yes... but is this function the ORIGIN of the maniraptoran wrist
structure, or is it BECAUSE of the pre-existing structure that 2ndary
flightless maniraptorans were able to adapt to a terrestrial predatory
niche? Chicken and egg stuff, if you ask me (and what an apt metaphor!)

-- 
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Dann Pigdon                   Australian Dinosaurs:
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://www.alphalink.com.au/~dannj/
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