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Re: Screaming dromaeosaur biplane killers of the air



Kris Kripchak (MariusRomanus@aol.com) wrote:

<are you saying that *Archaeopteryx* was no where near being a flier??? I
get the impression that you said this hasn't been shown either way... but
you seem to be deriving your opinions as if it has been. I'm confused.>

  No one has proven *Archaeopteryx* could or could not fly. It is a truly
equivocal issue. Proponents of flight allude to the broad and deep wing,
and the presence of asymmetrical primaries as evidence for flight, but
using Paul's "neoflightlessness" data, one can easily derived these from a
non-flying or a gliding descendant of a flyer. Similarly, *Archaeopteryx*
has a laterally-faceing glenoid that is emarginated on its dorsal rim,
preventing dorsal extension of the humerus, and lacks a humeral elevator
as well as any evidence it had much in the way of a sternum. Given the
presence of large sterna in less-well-preserved fossils from younger
lagerstätten, included fused complexes, this is curious and eitehr derives
a loss, as Paul advocates, or it never had one to begin with, and its a
sideline of low pectoral volume glider/poor flier....

  The work of Burgers and Chiappe, unfortunately, did little to show that
*Archaeopteryx* had the equipment to propell itself, depsite the size of
its wings, by arm action alone. *Archaeopteryx* may very well be the
quintessential hoatzin-analogue, despite repeated restorations in the air
(of which I, too, am guilty of).

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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