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RE: New in CJES
Jaime Headden wrote-
Zhou Z.-h., L. M. Chiappe & Zhang F.-c. 2005. Anatomy of the
Early Cretaceous bird *Eoenantiornis buhleri* (Aves:
Enantiornithes) from China. _Canadian Journal of Earth Sciences
- Revue de canadienne sciences du Terre_ 42(7):1331-1338.
Mickey Mortimer can probably say more about this paper than I can.
Well, Zhou et al. provide a much-needed redescription of this specimen. They
correct some statements of Hou et al. (1999). For instance, the sternum has
typical enantiornithine posterolateral processes with expanded tips, as well
as the smaller pointed posteromedial processes illustrated by Hou et al..
So the sternum isn't more primitive than Sinornis et al.. The teeth are
contained in separate sockets, not a groove. This makes it more like other
enantiornithines (Sinornis, Vescornis) and limits the presence of a groove
to Ornithurae sensu Chiappe. There is a medial wall to the antorbital
fossa, apparently containing a fenestra. The absence of an external
mandibular fenestra (and much of the mandibular anatomy) cannot be
established. Contra to either paper, there seem to be only ten cervicals,
as the eleventh has an elongate rib. The number of sacrals is more than
five, but cannot be stated to be 6-8 (contra Hou et al.). The coracoid
appears more elongate than illustrated by Hou et al., so is not intermediate
between other enantiornithines and Archaeopteryx. Basically, it's not
obviously primitive like Hou et al. suggested, and is more similar to
standard enantiornithines. Which makes sense, given basal taxa like
Jibeinia have derived sternal and coracoid morphologies. I reconstructed
the skull based on Zhou et al.'s figures-
http://students.washington.edu/eoraptor/Eoenantiornis%20skull2.jpg
Compare to Hou et al.'s reconstruction-
http://students.washington.edu/eoraptor/Eoenantiornis%20ori.jpg
Note the snout is longer, resembling other enantiornithines, and any
resemblence to Caudipteryx or Omnivoropteryx (as suggested by Czerkas and
Ji) is minimal.
Oh, and to answer David's question... no phylogenetic analysis is performed
in the paper. By 'analysis', Zhou et al. merely mean their identification
of characters synapomorphic of certain clades (Euenantiornithes) in
Eoenantiornis.
Mickey Mortimer
- References:
- New in CJES
- From: "Jaime A. Headden" <qilongia@yahoo.com>