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Re: Ramblings & questions



Dino Rampage (dino_rampage@hotmail.com) wrote:
 
<1) I understand now that the majority of restorations & reconstructions
of  "Oviraptor philoceratops" are actually of Citipati sp. So what did the
 'real' O. philoceratops look like? Was its cranial ornamentation any 
different? And what about C. osmolskae? What sort of headgear did it
flaunt?>

  This whole situation is really hard to explain without a slide show, one
reason i set up my site to begin with; and though I have pages on
*Rapator* and *Titanosaurus colberti* up, the oviraptorosaurian pages have
given me a hard time in the making. However, I will try to be clear on
this as best I can:

  1) do not use my portraits on the new Dinosauricon as a guid to head
gear, for even though i followed the skulls, these are interpretations of
my own as to shapes, for I added keratin over bone and thus changed
shapes, plus I "fixed" the crest of *Oviraptor mongoliensis* somewhat,
making it shorter to compensate for what I perceive to be some flattening
and correlated crushing of the crest.

  2) Oviraptorid head gear fall along two lines: up, and forward.
*Citipati osmolskae* (GI 100/979) has a crest that points _forward_
slightly, and may expand some more as the skull may not be fully mature.
This is the same in GI 100/42 (*Citipati* "sp.") and the skull GI
100/2112, recently mentioned by Mickey. There are more skulls out there
with head gear that compare. In GI 100/42, the crest is slightly raised
above the head, but it is essentially a rostrally-projecting plate. One
only oviraptorid has a dorsally, pointing _up_ crest: *Oviraptor
mongoliensis* GI 100/32A, which has no rostral expansion and in fact seems
to lean backwards in some ways (more on this later). *Oviraptor
philoceratops* (AMNH 6517) is represented by a skull that is missing
nearly the entire dorsal part of the skull above the orbits, preserving
parts of the nasal, frontal, and most of the parietal. In the fossil, the
parietal is a large, flat rectangle of bone as in *O. mongoliensis* and is
disarticulated slightly caudally, but rotating it forward still results in
a high, sagittal keel. You do not see my portrait of this animal on the
Dinosauricon yet because I am very cautious now about "devising" the
skull: the premaxilla and most of the nasal are missing, and this will
seriously effect the skull's shape.

  3) no other oviraptorid has a cranial crest with the possible exception
of the holotype of *Ingenia yanshini* (GI 100/30) which includes the
braincase, parietals, frontals, and a portion of the nasals. It is unknown
whether this skull originally sported something of a crest. Both *Khaan
mckennai* (GI 100/1127 and 100/1002) and *Conchoraptor* (GI 100/20) lack
crests.


<2) Is it generally accepted that Elmisaurus was also present in North 
America?>

  No. Sues (1998) refers the species as a form of *Chirostenotes* and
synonymous with *C. sternbergi*. However, many other workers, including
Currie, Russell, and Varricchio consider the name and appelation to
*Elmisaurus* as valid. Sues' criteria is based on size.

<4) I keep hearing that the asian hadrosaurs of the Tsagayan and Barun
Goyot are different from those in the Nemegt. What are the exact taxa from
all these formations? And what do they mean that there was a mass
extinction of asian hadrosaurs after the tsagayan, only to be replaced by
american immigrants?>

  Iguanodonts of the Barun Goyot are:

  nil.

  In the Tsagayanskaya Svita:

  "Mandschurosaurus" amurensis Riabinin, 1925
  "Tanius" sinensis Wiman, 1929, which may be *Bactrosaurus*, albeit a
late-surviving one. [*Tanius* is also identified from the Wangshi Series]

  Both of these are very crappy in remains.

<5) Shantungosaurus is Campanian?>

  Depends on the dating of the Wangshi Series. You also get
*Tsingtaosaurus spinorhinus* from this level along with the aforementioned
*Tanius sinensis (=chingkankouensis)*.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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