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The Beak of *Confuciusornis*: My Thoughts on All Those Pretty Birdies



  The Beak of *Confuciusornis*: My Thoughts on All
Those Pretty Birdies

    INTRODUCTION

  Lately I've been pouring through the literature and
doing a lot of comparative work -- I don't know what's
gotten into me. Recently, I got my hands on Chiappe,
Ji, Ji, and Norell, 1999 [thanks, Mickey!] and was
finally able to sit down with the papers of
confuciusornithids, per the discussion I shared with
Dwight, Mickey, and others on the subject. Generally,
I liked the paper, but for 89 pages, there was a lot
to be desired, and I'm beginning to get the feeling
that the _Bulletins_ / _Novitates_ / _Nature_ articles
coming from the AMNH group et al. are a bit rushed in
prep and narrow in scope.

  Simply, the subject of this thread ended around
wondering if *C. dui* was diagnostic or valid, and
especially centered around the upturned, "Woody
Woodpecker" beak present in recurvirostrids
(Charadriiformes: Aves) and "rhamphorhynchids" and
dsungaripterids (Pterosauria).

    SYSTEMATICS

  Chiappe et al., 1999, state that they cannot verify
or deny the validity of *C. dui*; pity. Just reading
the poor description by Hou et al., 1999, and
comparing it to Chiappe et al., 1999, to both *C.
sanctus* and *Changchengornis hengdaoziensis* (Ji et
al., 1999), it seems to me there is a paucity of
information presented to indicate the validity of *C.
dui*; the variation within *C. sanctus* is expressive,
with only slight shape variation with animals 40%
smaller than the largest specimens; the holotype of
*C. dui* (IVPP v11553) falls below this range, at
175mm compared to 241-200mm in *C. sanctus* (20%
smaller than smallest complete specimen studied), but
exhibits relative "adult" appearance of the skull, not
the slender, delicate form seen in smaller, "younger"
specimens (Chiappe et al., 1999); and of special note,
does not have a ventral process projecting from the
dorsal surangular bar into the external mandibular
fenestra (and yes, I have thought of oviraptorids in
this respect: different morphology, rounded and not
prong-like, projects from the rod and not the base of
the bone, ...). *C. dui* is interesting, has a
tab-like caudal projection of the sternum (xiphoid
process -- in refered specimen IVPP v11521) distinct
from the triangular projection in several *C. sanctus*
species; the manal claws are supposedly straiter than
in *C. sanctus*, but Chiappe et al. describe a
skeleton (GMV 2130) of the latter species that has the
claw curvature shallow on one arm, and trenchant on
the other.

  Anyway, smaller apparent adult size and distinct
sternal process are the only characters apparent to me
that suggests *C. dui* is a unique species -- it
shares very little with *C. hengdaoziensis* that
aren't general to Confuciusornithidae.

    THE BEAK OF *C. DUI*

  The holotype of *C. dui* is strange in that it
preserves a keratinous outline that curves upward a
little; the osseous beak does not, as in all skulls of
*Confuciusornis*, except for particularly small (60%
full size) individuals where the tip turns up. Some
remarks on the beaks of *Confuciusornis* not described
(at least in English -- I haven't read the German and
Chinese papers) is that the lower jaw is longer than
the upper, even basal length, and articulated skulls
show this quite distinctly. Taking extensive
measurements when reconstructing the skull, this was a
greater length of about 2mm or so in most skulls in
Chiappe et al., 1999, in Hou et al., 1999, but not Hou
et al., 1995 [don't worry, refs at the end]. Funny
enough, the specimens described and figured by Chiappe
et al. do not preserve keratinous beaks, though head
feathers, apparent eyeball carbon traces, and some
trace outline is preserved. Thus the shape of the beak
cannot be determined by me, but someone out there
should have some notes from the numerous fossils shown
at SVP last year or have seen more photos that
preserved the beak. The point is, though Hou et al.
1999 advocate an herbivorous diet, and Chiappe et al.,
1999, do not discuss diet, there are several features
of the birds that _do_ suggest an alternative diet,
and I mentioned this previously. The wings taper
narrowly with a low aspect ratio (preventing stall at
low speed, such as skimming water), the lower beak is
longer than the upper, and the beak is turned upward,
suggesting it fed on fish, not plants.

    REFERENCES

  Chiappe, L.M.; Ji S.-A.; Ji Q.; and Norell, M.A.
1999. Anatomy and systematics of the
Confuciusornithidae (Theropoda: Aves) from the Late
Mesozoic of Northeastern China. _Bulletin of the
American Museum of Natural History_ 242: 89pp.

  Hou L.-H.; Martin, L.D.; Zhou Z.; Feduccia, A.; and
Zhang F.-C. 1995. A diapsid skull in a new species of
the primitive bird *Confuciusornis*. _Nature_ 399:
679-682.

  Hou L.-H.; Zhou Z.; Martin, L.D.; and Feduccia, A.
1995. A beaked bird from the Jurassic of China.
_Nature_ 377: 616-618.

  [Images from the website show up better than
photocopies of the article when printed off a laser or
inkjet, so I suggest acquiring the figures from there,
too; the website http://www.nature.com allows
non-subscribers to search for articles, and access
supp. info. or figs., along with the abstracts]

  Ji Q.; Chiappe, L.M.; and Ji S.-A. 1999. A new Late
Mesozoic confuciusornithid bird from China. _Journal
of Vertebrate Paleontology_ 19 (1): 1-7.

=====
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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