From: Dann Pigdon <dannj@alphalink.com.au> Reply-To: dannj@alphalink.com.au To: DML <dinosaur@usc.edu> Subject: Re: the maniraptoran wrist Date: Sun, 15 Sep 2002 10:44:14 +1000
"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!)
-- ________________________________________________________________
Dann Pigdon Australian Dinosaurs: GIS / Archaeologist http://www.geocities.com/dannsdinosaurs Melbourne, Australia http://www.alphalink.com.au/~dannj/ ________________________________________________________________