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RE: Parahongshanornis, new Chinese Cretaceous bird (free pdf)
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- Subject: RE: Parahongshanornis, new Chinese Cretaceous bird (free pdf)
- From: Mickey Mortimer <email@example.com>
- Date: Wed, 1 Jun 2011 14:41:45 -0700
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Tim Williams wrote-
> True. But what's not normal about _Patagopteryx_ is that (a) the 2nd
> phalanx of the 2nd fnger is the longest, and (b) the wings were not
> used for flight.
Agreed on point b, but II-2 being longer than II-1 is just a symplesiomorphy.
It's also seen in Hongshanornis, Longicrusavis, Parahongshanornis, some
Yanornis and Protopteryx, so was probably retained from the ancestral condition
and lost convergently in derived enantiornithines, derived ornithuromorphs,
Changchengornis, omnivoropterygids, Jixiangornis, Dalianraptor, derived
ingeniines, some parvicursorines, etc..
> > I agree, though, that somebody should do a biomechanical study of the
> > forelimbs of *Patagopteryx* (which I'm not confusing with *Patagonykus* this
> > time).
> At a glance, _Patagopteryx_'s two-handed grasping abilities don't seem
> much worse than those of certain non-avian theropods, like
It would certainly be an interesting study, with Patagopteryx's combination of
primitive and derived features. However, note that the second digit is much
smaller than Caudipteryx, about equal to metacarpus length instead of over
twice as long. Similarly, the ungual is more poorly developed. Perhaps most
damning is that the first digit seems to be absent, since there is a keel where
it would normally be placed.