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Re: Oviraptor



<[I] have several questions about Oviraptor phylogenetic position. At first
Oviraptor is the oldest mongolian oviroptorid. Other, such as Khaan or Citipati
are from Ukhaa Tolgod which relates to younger Baryn Goyot Formation (Alifanov,
pers. comm.).>

  I personally am not sure about Alifanov's data, though I cannot contend with
it on its face (since I don't know what it is). Nearly all the biogeographic
comparative data with the Ukhaa Tolgod fauna relates almost perfectly with the
Djadokha Formation, and implies that, by bearing many reptile taxa in common
with Bayn Dazk (Bayan Zag, Bain Dag, etc.), it is most likely related to that
formation horizontally stratigraphically. This means *Khaan* and *Citipati*,
along with *C. sp.* (which is Djadokhtan on other factors) are of a likely
Cenomanian or basal Campanian age [lower to middle Senonian].

<Second, the snout of Oviraptor was more elongate than in other oviraptorids
(Clark et all., 2002), I think it is a primitive characteristic.>

  This is generally correct, given the idea that oviraptorids had
developmentally shortened snouts than in their relatives; however, more
primitive oviraptorosaurs tend to have snouts just as short relative to jugal
length, or the maxilla is relatively shorter than in *O. philoceratops*
comparatively, as in the *Chirostenotes* snout that Sues described in 1997, when
associated with a mandible described as *Caenagnathus.* This gives *O.
philoceratops* a possible apomorphically longer snout than in its potential
outgroup. Otherwise, I would agree that this is the basal condition.

<So I think That Oviraptor is more basal oviraptorid that Ingenia,
Khaan+Conchoraptor and "Rinchenia"+(Citipati+Citipati sp.+new taxon). If it is
right?>

  Most likely. There is research going out on this subject, and Clark et al.
(2001, 2002) indicate this subject is likelier than not. For the most part.
*Conchoraptor* requires some comparative understanding: only the left side of
the skull is known, and the palate is virtually absent along with the front of
the mandible and much of the braincase has an eroded surface on the one exposed
face. *Khaan* is not fully prepared as yet, and *Citipati* has an unprepared
(being done) and undescribed skeleton. *Oviraptor mongoliensis* has a partial
skeleton including verts and such, but this has remained undescribed since its
recovery in the late 1970s, though Barsbold et al. (1990) figured the partial
ilium. Lü designated his Chinese find as *Ingenia* on the basis of the pelvis
and sacrum, and to some degree, he is very pertinent on this: based only on the
hand, *Ingenia* compares well to *Heyuannia*, but its skull is largely unknown,
so it may have had the crest (only *Conchoraptor* and *Khaan* certainly didn't
have one), and Lü's find may pertain to *Ingenia* after all, as both possess a
supernumerary sacral count, otherwise seen in the "caenagnathid?" *Nomingia.*

  As for figures or pictures of troodont postcrania, this is very rare and the
best skeletons are undescribed, not well (*Saurornithoides mongoliensis* and *S.
junior*) or briefly described (as in *Sinovenator*), or are being prepped for
description (Ukhaa Tolgod troodontid, maybe *Byronosaurus*). The postcrania of
*Sinornithoides* is figured in one fantastic page, and *Byronosaurus* is limited
to a few vertebrae and a knee; GI 100/44 is a young animal with poorly-preserved
bones that reveal little about the affinities of the form except that it, like
*Sinovenator*, possessed a non-arctometatarsalian foot and the second metatarsal
was not narrowed at midlength, narrowed in all other troodontid pes including
*Tochisaurus* and *Borogovia,* which also have the arctomet (these two taxa are
limited to partial legs). The last two are available if you cannot get them in
the original papers, and Mickey Mortimer has a fantastic scan of the figures of
*Sinornithoides* to help.

  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.

  "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)