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Re: CNN report on the feathered dino



I was slightly ambiguous in my phrasing in my earlier response to this post.
I've attempted to rectify that herein.

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Williams, Tim wrote:

> The long, planar feathers on the arms and legs would add additional drag to a
parachuting descent - and offer the
> potential for generating an airfoil.

If oriented more or less aft, wouldn't they reduce drag by increasing the
fineness ratio?  An object with a fineness ratio on the loose order of 3 to 5
has up to 25 times LESS drag than a right circular cylinder of the same
thickness.  This would be true even if the feathers aren't pointed aft, as long
as they are oriented in a way that increases the fineness ratio.

> Though useful in parachuting or gliding descents, hindlimb feathers would
> undoubtedly be a hindrance in a running take-off from ground level.

Not necessarily true, would likely be an advantage -- see above.

> Also, from the CNN story, "Norell said that some modern birds such as
> certain kinds of hawks have big feathers sticking out of the back of their
> limbs.."  Does anyone know why?

See above, though I'm not attempting to imply that is the actual reason some
hawks display this feature.

Jim