Re: Primates and proavians (was Re: [RE: A glider?])

[Richard W Travsky <rtravsky@uwyo.edu>]

On Thu, 26 Apr 2001, Tim Williams wrote:
> Ronald Orenstein wrote:
> 
> >I am not one for jumping to conclusions, but it would certainly be
> >interesting o compare the structures on the forearms of this animal with
> >the hair on the arms of South American sakis, which (if they do not
> >actually glide) can make very extensive leaps apparently using the forearm
> >hair for a bit of extra lift.  mind you, I wonder how this can work if the
> >hairs are not stiffened?
> 
> 
> This has also been described in another group of primates, the sifakas 
> (_Propithecus_ spp.) from Madagascar.  Sifakas have a "brachial mat" of 
> hair, which is useful in maneuvering the animal through the air during leaps 
> (not true glides).  The person who described this behavior (and actually 
> suggested it as an analog for a hypothetical tree-jumping proavian) was none 
> other than Al Feduccia!

I had done a quick web search on sakis and found the Feduccia mention.

 http://www.cmnh.org/fun/dinosaur-archive/1996Sep/0202.html

 Darren Naish (dwn194@soton.ac.uk)
 ...
 ...Feduccia has published two papers where these features are interpreted
 as analogies to the earliest feathers. One was published recently in
 _Courier Ferchung._, and the other a couple of years back in _Jour.
 Theoretical Biology_. 

and

 http://www.cmnh.org/fun/dinosaur-archive/1996Sep/0211.html
 Ronald Orenstein (ornstn@inforamp.net)
 ...
 Feduccia was referring to sakis, not sifakas. From p. 97:

 "Among New World primates, which lack prehensile tails, there are
 numerous semi-aerial adaptations, and the sakis of the genus Pithecia are
 notable among them. Pithecia monachus, known locally as volador (flier),
 has a long body, with moderately long arms and legs, and its pelage, or
 body hair, is a distinctlve long, rather coarse, grizzled blackish fur.
 Sakis prefer mature moist forest.... where they frequently glide in
 flying squirrel fashion."

 Feduccia compares their gliding abilities to those of sifakas (they are
 apparently a lot better at it) and includes photos of both.


Interesting. Hadn't considered this in primates.

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