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Quill knobs preceded by "superglue" cartilage??




I was going to make a joke and suggest "superglue". But that got me to thinking, maybe "super-cartilage"? Couldn't a broad strip of cartilage be attached to the ulna (without having left any obvious osteological evidence) that would have been strong enough to anchor feathers in early "weak fliers". Then perhaps quill knobs would have then been the evolutionary breakthrough that allowed stronger and stronger fliers as "quill knob design" improved? Could this explain how Rahonavis got by with such small quill knobs?
Just a thought, Ken
********************************************************
From: "ptnorton" <ptnorton@email.msn.com>
Reply-To: ptnorton@email.msn.com
To: <Mickey_Mortimer11@email.msn.com>, <dinosaur@usc.edu>
Subject: Re: Longipteryx chaoyangensis (Aves, Enantiornithes?)
Date: Thu, 31 May 2001 19:00:00 -0400

Mickey Mortimer wrote:

> Archaeopteryx and Caudipteryx definitely lack ulnar quill knobs.  The
specimens have been examined thoroughly and are well preserved. <

I've wondered for a long time why researchers haven't raised more questions
about the apparent absence of quill knobs on Archaeopteryx in particular,
given all the work that has been done analyzing its flight capabilities.
Implicit in all the analyses of Archie's flight capabilities is the
assumption that the elongated feathers of the arm formed a rigid airfoil.
The only way that is possible is for those feathers to be anchored to the
arm bones---and feathers anchored to bone would almost certainly leave some
osteological evidence. Perhaps that evidence simply hasn't been preserved
in all cases. But it seems that one would need an entirely novel
explanation of the mechanics of feathered flight to argue that those animals
flew using feathers that weren't somehow anchored to the bones of the arm.


PTN

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