Re: "Flight theory has legs"

[Graydon <oak@uniserve.com>]

On Sun, Jul 13, 2003 at 10:07:30PM -0700, James R. Cunningham scripsit:
> Graydon wrote:
> > What I was also trying to say is that you're also trying to provide a
> > counterbalancing downward force so you can slice harder without going
> > springing away; 
> 
> How do you go about creating this additional downward force (creating it
> for the body, not the legs)?  Why not just create it for the legs only?

If you have feet that can grip,  you'd do that.

Everything I've seen about dromeosaur feet indicates that they can't do
that; hallux isn't reversed, toes three and four don't curl under, etc.
You could maybe have a scenario where you get one sickle claw stuck and
then use the other one, repeat as necessary or convenient, but that
seems implausible; those claws are slicers rather than (rounder
cross-section) anchors.

How you get the extra stickiness from flapping I'm not sure; I think it
depends a lot on how complex a range of flapping is available.

If the trunk is vertical (or near to vertical) beside a much larger prey
animal that the feet are in contact with, I can see a flapping angle
being available that would generate thrust that was up and in (something
that would go along with the wing assisted vertical running hypothesis)
but have no idea how one would go about setting up a biomechancial
analysis of that hypothesis.

-- 
oak@uniserve.com | Uton we hycgan    hwaer we ham agen,
                 | ond thonne gedhencan    he we thider cumen.
                 |   -- The Seafarer, ll. 117-118.