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RE: Of course nonavian dinosaurs could fly - duh

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Graydon wrote:

<Willow Ptarmigan have extensive foot-feathers and run fine. Various showy =
bantam chickens with really extensive foot feathers also run fine.

It's an argument against being selected for some kinds of cursorial ability=
=2C maybe=2C but it's not an obvious indication of cursorial inability.>

=A0 Ptarmigan in this sense have very short feathers on the feet and=2C ike=
 snowy owls=2C use them to walk on or dig in snow=2C where the added surfac=
e area of the feet is advantageous.=A0 If you thought this would not be a h=
inderance to running on hard ground=2C I suggest an experiment wherein some=
one goes to a rocky ground and try running with snowshoes on.

=A0 However=2C these feathers are different in another way: The feathers of=
 the microraptorians and now *Anchiornis* are elongate=2C apparently arraye=
d in the same plane as the direction of leg movement (although this could b=
e an artifact of preservation)=2C and when abraded on rough substrate=2C on=
ly the tips would be damaged.=A0 This would=2C as Denver said=2C matter eve=
n if the animal was running on a branch broad enough to support a running s=
urface for both feet.=A0 If the animal was incapable of moving them out of =
the way=2C i.e=2C. folding as in the primaries=2C then they would show dama=
ge to the tips.=A0 They do not.=A0 However=2C right now=2C none of us can a=
ssert with even more 50% confidence what the feathers were used for _and ba=
ck it up_ (which means _Dinosaurs of the Air_'s proposition and its assumpt=
ion of a dislocatable hip joint is right out).


Jaime A. Headden

"Innocent=2C unbiased observation is a myth." --- P.B. Medawar (1969)

"Human beings=2C who are almost unique in having the ability to learn from =
the experience of others=2C are also remarkable for their apparent disincli=
nation to do so." --- Douglas Adams (Last Chance to See)

"Ever since man first left his cave and met a stranger with a different lan=
guage and a new way of looking at things=2C the human race has had a dream:=
 to kill him=2C so we don't have to learn his language or his new way of lo=
oking at things." --- Zapp Brannigan (Beast With a Billion Backs)

> Date: Sat=2C 26 Sep 2009 16:37:04 -0400
> From: oak@uniserve.com
> To: GSP1954@aol.com
> CC: dinosaur@usc.edu
> Subject: Re: Of course nonavian dinosaurs could fly - duh
> On Sat=2C Sep 26=2C 2009 at 10:35:45AM -0400=2C GSP1954@aol.com scripsit:
>> The authors of the Anchiornis paper are correct that animals with such
>> extensive foot feathers are unlikely to have been well adapted for
>> running about on the ground.

> -- Graydon
Bing=99  brings you maps=2C menus=2C and reviews organized in one place.   =
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