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Re: The beak of C. dui



Dan Bensen wrote:

<I was just reading about the new species of
Confuciusornis that's been recently discovered, C.
dui. This bird has larger wings then C. sanctus, very
small feet, and a strange, upturned beak. The beak
tapers downward like normal birds until the tip, where
it the beak of the upper mandible suddenly switches
direction and bends upwards.>

  This is what prompted the popular press to dub *C.
"dui"* the Mesozoic Woody Woodpecker. However, had
they ever had the fortune of looking at other fossils
than what's in Nature or Science, they would have seen
fossils described since the 1700's with upturned
woody-schnozolas: rhamphorhynchid pterosaurs. Kinda
hard to described this all without pictures, and my
head studies of most of the species and all the
relevant genera of the Rhamphorhynchidae (excluding
*Dendrorhynchoides* until I can actually _see_ the
skull is better detail than Ji et al.'s 1999 blurb)
are presently unscanned. All rhamphorhynchids have
upturned bony rostra, except for the premaxillaries in
one species of *Rhamphorhynchus* (R. gemmingi) and in
*Scaphognathus*. However, the lower jaw is quite
derived in these taxa relative to *Confuciusornis*.

  A few difficulties, however, in Hou et al's (1999)
description of the new species: it was never compared
to the other two species described for the genus
(later deconstructed by Chiappe et al. (2000), as for
this species) or was compared to the other species to
check for intrageneric or -specific variation.

<At first I thought it might be some kind of mechanism
for catching fish, but such a mechanism would make the
_bottom_ mandible bigger, not the top. Can anyone give
any insight as to what this bird, with its big wings,
small feet, and weird beak did for a living?>

  Some charadriiform birds have upturned rostra (like
the recurvirostrids [turnstones, etc.]) with which
they use to probe under stones, or flip them over, to
pry open clams/oysters, etc. The upturned bill
decreases stresses to the dorsal surface of the beak,
bony or keratinous, and so effort applied in the
direction of the curve reduces resistance, and
increases the bird's ability to open the clam or flip
the stone. Such a function can be applied to
*Confuciusornis* (note: a perfectly strait bill is
required for the woodpecker "drill" adaptation, for
translation of force directly through the skull into
the spine).

  Small feet probably translates to increased
terrestriality as opposed to arboreality, due to big
feet for grasping branches. Wings, flight. Aspect
ratio is really the important thing here, but do the
wings taper significantly?


=====
Jaime "James" A. Headden

"Come the path that leads us to our fortune."

Qilong---is temporarily out of service.
Check back soon.

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