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RE: Evidence For a Feathered Velociraptor...
Mickey Mortimer wrote:
> Penguins no longer have remiges, but still have quill knobs.
The situation regarding quill knobs is apparently a little complicated in
penguins. Some penguins have 'pits' rather than knobs
along the ulna. So do the extinct plotopterids, apparently. Says Mayr (2004;
"A highly characteristic derived peculiarity of the ulna of plotopterids is the
presence of a row of marked pits for the attachment
of feather quills (Olson 1980, Fig. 3; Olson and Hasegawa 1996, Fig. 6D). Olson
(1980, p. 55) considered this to be 'a unique
condition in birds, and quite unlike that in penguins in which the remiges can
no longer be differentiated from other feathers of
the wing'. However, a similar row of pits, although less marked, is found in
some modern penguins (_Eudyptes_, _Eudyptula_,
> Dodos are flightless but have quill knobs. Kagus are almost flightless, but
> have large quill knobs. The largest knobs are
> present in roadrunners and go-away birds.
Turner et al. (2007; Supp Info) make the argument, using Livezey and Zusi's
(2007) dataset, that there is a statistically
significant correlation between quill knobs and powered flight, despite the
absence of quill knobs from certain volant taxa, and
the presence of quill knobs in certain flightless taxa. However, all modern
birds are descended from a most recent common
ancestor that was flighted (and presumably possessed quill knobs), so it is
difficult to extrapolate to non-avians (or maybe even non-ornithurans).
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