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RE: Parahongshanornis, new Chinese Cretaceous bird (free pdf)



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
> caudipterygids.

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.

Mickey Mortimer