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Re: Udanoceratops



HP Dan Bensen wrote:

<I was making a little reconstruction of
Udanoceratops, a Mongolian ceratopsian much like
Leptoceratops.  Unlike its relatives, however,
Udanoceratops has a very deep jaw, large nostrils, and
eyes set far up (that is, skyward) on its face. HP
Headden's picture of the skull is posted on the
Dinosauricon (look in the genus list for
Udanoceratops). Could these unusual adaptations be for
a partially aquatic niche like a hippo? (according to
the Dinosauricon) Udanoceratops _is_ the largest of
the bipedal ceratopsians and a partially aquatic
lifestyle could explain the gigantism. What other
interpretations for its weird skull are there?>

  *Udanoceratops tschichovi* is an unsual
non-coronosaur neoceratopian that has not been
extensively described (once by Kurzanov, then zippo).
The skull, however, possesses two unique features that
can suggest the function of its unusual jaw. First
off, I will ask a question: What functional
implications can be derived from the type of jaw seen
in *Udanoceratops* (and also in *Leptoceratops
gracilis*, a monophyletic Leptoceratopidae)?

  The lower jaw is ventrally bowed on both the tooth
row and the ventral margin, and the maxilla is
ventrally bowed to match; secondly, the facial bones
have a highly ornate surface composed of depressions
and low crests. There is an extant analogue I found
when reconstructing the skull, *Alouatta* (the howler
monkeys). I had intended to put a page on Qilong
sometime about a year ago, but was not able to do it
at that time, and should try now. They're _very_
peculiar group of ceratopians, leptoceratopids.

  I'll pause on this for now.

<I looked at a skeletal reconstruction of
_Protoceratops_ for comparison, and P.'s eyes are set
fairly high up as well, so the eyes may not be an
adaptation for any particular kind of life _per say_,
but a phylogenic quirk. I would appreciate anything
anybody has to say on the matter.>

  This is probably related to the enlarged jaw
structure and enforced vertical compressions when
biting would be reduced by a deeper jaw. The
hypothesis would need to be tested, but since I don't
have the neccessary equipment right now....

=====
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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