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RE: Science feather strength debate





> Date: Wed, 3 Nov 2010 21:06:41 -0300
> > Many coelurosaurs have elongated forelimbs, although those of
> > _Archaeopteryx_ are among the longest (outside Ornithothoraces).
> > However, there is no reason to automatically assume that forelimb
> > elongation in a feathered non-ornithithoracine theropod is
> > flight-related.  Longer forelimbs also improve reach - such as for
> > prey capture (e.g., dromaeosaurs), or procuring branches (e.g.,
> > therizinosaurs), or possibly climbing (e.g., _Yixiansaurus_,
> > _Epidendrosaurus_).
> 
> All possibilities, but one can say, using the EPB, that these
> considerations imply behaviours (and thus parts of soft anatomy) that
> are not primitive for the two extant clades bracketing Archaeopteryx,
> while flight is for one of these clades (and thus would lead, at least
> for this behavior, to a more parsimonious character evolution
> hypothesis). Of course EPB is not all there is in life, and you also
> have mechanics, but then one can doubt, as one doubts of the flight
> capabilities of Archaeopteryx, how good are the long stiff fingers of
> Archaeopteryx in grasping prey, and, as you previously indicated in a
> former discussion with me, that the general anatomy of Archaeopteryx
> does not suggest it to be quite a climber (branch procuring for such a
> small animal should be related to climbing and to the deficient
> grasping capabiities of the hand).

 Would it be easier for fingers to get less stiff, or more stiff?   (it seems 
to me that it would be former, not the latter)


e.g. monkeys and sloths can both reach for branches, but monkeys have hands 
capable of more tasks  -  so monkeys would have an advantage over sloths...but 
sloths still have a mobility advantage over tree-dwellers with less hand 
mobility, such as jaguars.

  do we see a similar pattern in the fossil record, with greater manus mobility 
giving more opportunities and helping the survival of avian (and pre-avian) 
theropods  against their stiffer-fingered theropod relatives?