Gliding primates?

[Dunk]

Brachiating and even leaping within/between trees is a primate
specialty. Evidently binocular vision helps or may even be
necessary.

But it seems that primates never glide. Or do they? Do any
primates, leaping with great 'halos' of stiff hair, get any
aerodynamic lift or steering at all?

And, if you happen to know, do some gliders have
binocular vision?

Dunk

ps this: http://www.luisrey.ndtilda.co.uk/html/chinesenov.htm
but not this with the rubber legs
http://cn.oursci.org/newsimage/2003/012301-3.jpg is in the
back of my mind as I post.

[Marc Verha]

"Dunk" <pdunkel@paleblue.net> wrote in message
news:3e31802a.2112125@news.earthlink.net...

> Brachiating and even leaping within/between trees is a
> primate specialty.

Not only primates: phalangeroids, squirrels, tupaias,
birds, geckos...

> Evidently binocular vision helps or may even be necessary.

Probably not: it's now believed that binocularity evolved in
fruit-eating pre-primates to catch insects.

> But it seems that primates never glide. Or do they?

The nearest relatives of primates do glide: dermoptera.

> Do any primates, leaping with great 'halos' of stiff
> hair, get any
aerodynamic lift or steering at all?

Tarsiers, eg, have "feathered" tails, which help in
steering etc.

> And, if you happen to know, do some gliders have
> binocular vision?
Dunk

Dermoptera have much less binocular eyes than primates.

Binocularity (overlapping eye fields) is no question of all or
nothing. Prey species in open terrain, eg, hares, need
panoramic sight (almost 360°), hence no binocularity.
Predators always have some binocularity (to fixate the prey
before catching it). But "full" binocularity (mostly
overlapping fields) is typically seen in cats, owls,
primates... AFAIWK, "full" binocularity evolves (only?) in
predators on small & fast preys. IMO a necessary factor for
"full" binocularity as in primates was crepuscularity or
nocturnality or at least living in dark forests, where the
information from one yes needs confirmation by that of the
other eye (cf. cats, owls).

Marc

[Harry Erwi]

Dunk <pdunkel@paleblue.net> wrote:

> Brachiating and even leaping within/between trees is a
> primate specialty. Evidently binocular vision helps or may
> even be necessary.
>
> But it seems that primates never glide. Or do they? Do any
> primates, leaping with great 'halos' of stiff hair, get any
> aerodynamic lift or steering at all?
>
> And, if you happen to know, do some gliders have
> binocular vision?
>
> Dunk
>
> ps this:
> http://www.luisrey.ndtilda.co.uk/html/chinesenov.htm but
> not this with the rubber legs
> http://cn.oursci.org/newsimage/2003/012301-3.jpg is in
> the back of my mind as I post.

<ASIDE>Am I fated to respond automatically to certain
keywords?</ASIDE> Ignacius and Phenacolemur may have been
gliders. There is a suspicion they were ancestral to the
Dermoptera. Modern primates don't glide (except Homo), but
they certainly leap, and they use their tails and limbs to
help steer their leaps. See Oxnard, the Oxnard of Man. That
said, I suspect the patagium would get in their way too much
and be too easily damaged. Most gliders move around in trees
more like squirrels or colugos/bats than Primates.
--
Harry Erwin <http://www.theworld.com/~herwin/

[Marc Verha]

"Harry Erwin" <herwin@theworld.com> wrote in message
news:1fpbc3a.ytod54le40foN%herwin@theworld.com...

> > Brachiating and even leaping within/between trees is a
> > primate
specialty. Evidently binocular vision helps or may even be
necessary. But it seems that primates never glide. Or do they?
Do any primates, leaping with great 'halos' of stiff hair, get
any aerodynamic lift or steering at all? And, if you happen to
know, do some gliders have binocular vision? Dunk

> Ignacius and Phenacolemur may have been gliders. There is a
> suspicion they
were ancestral to the Dermoptera. Modern primates don't glide
(except Homo), but they certainly leap, and they use their
tails and limbs to help steer their leaps. See Oxnard, the
Oxnard of Man. That said, I suspect the patagium would get in
their way too much and be too easily damaged. Most gliders
move around in trees more like squirrels or colugos/bats than
Primates. -- Harry Erwin

(Oxnard "The Order of Man", you mean.) Yes, don't most (all?)
gliders have claws? It's now believed that the early primates,
after they split from the early dermopterans, evolved grasping
hands to climb terminal branches to reach fruits. Grasping is
possibly incompatible with having claws, which could hurt the
hand when grasping. Dermoptera have retractile claws IIRC.
Gliders (always?) glide to tree stems or large branches, where
they can't use grasping hands, so possibly gliding & grasping
are incompatible? Ignacius & Phenacolemur are plesiadapiforms.
A recently found plesiadapiform is Carpolestes simpsoni, 56
Ma, no orbital convergence, no postorbital bars, no
adaptations for leaping, but euprimate grasping foot with
opposable hallux with a nail on it, but claws on the other
digits. EJ Sargis "Primate origins nailed" Sci.298:1564 (on
Bloch & Boyer 2002 Sci.298:1606) thinks Carpolestes might have
been a terminal branch feeder (mostly fruits?), but was not
very binocular (insects), unlike euprimates.

Marc

[Harry Erwi]

Harry Erwin <herwin@theworld.com> wrote:

> Dunk <pdunkel@paleblue.net> wrote:
>
> > Brachiating and even leaping within/between trees is a
> > primate specialty. Evidently binocular vision helps or may
> > even be necessary.
> >
> > But it seems that primates never glide. Or do they? Do any
> > primates, leaping with great 'halos' of stiff hair, get
> > any aerodynamic lift or steering at all?
> >
> > And, if you happen to know, do some gliders have binocular
> > vision?
> >
> > Dunk
> >
> > ps this:
> > http://www.luisrey.ndtilda.co.uk/html/chinesenov.htm
> > but not this with the rubber legs
> > http://cn.oursci.org/newsimage/2003/012301-3.jpg is in
> > the back of my mind as I post.
>
> <ASIDE>Am I fated to respond automatically to certain
> keywords?</ASIDE> Ignacius and Phenacolemur may have been
> gliders. There is a suspicion they were ancestral to the
> Dermoptera. Modern primates don't glide (except Homo), but
> they certainly leap, and they use their tails and limbs to
> help steer their leaps. See Oxnard, the Oxnard of Man. That

Whoops--Oxnard, the Order of Man

> said, I suspect the patagium would get in their way too much
> and be too easily damaged. Most gliders move around in trees
> more like squirrels or colugos/bats than Primates.

--
Harry Erwin <http://www.theworld.com/~herwin/

[Curious Am]

In article <1fpcnpo.1t2m1todxt2zgN%herwin@theworld.com>,
herwin@theworld.com (Harry Erwin) wrote:
>Harry Erwin <herwin@theworld.com> wrote:
>
snip
>> See Oxnard, the Oxnard of Man.
>
>Whoops--Oxnard, the Order of Man

Thanks Harry. For a minute I was wondering. ;-)

CA