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The New "Oviraptorosaurid" from China



Sorry, gotta mock these guys once in a while. Lü Junchang is an advocate
of the avialaean hypothesis of oviraptorosaurian relationships, a theory I
do not think holds much water. But more on that later.

  Lü J.-c. 2002. A new oviraptorosaurid (Theropoda, Oviraptorosaurid) from
the Late Cretaceous of southern China. _Journal of Vertebrate
Paleontology_ 22 (4): 871-875.

  Lü describes a new oviraptorid, *Heyuannia huangi*, named for Heyuan
City in Guangdong Province, south-central China, and for Huang Dong, who
is the director of the musuem where the specimens are located. That would
be the Heyuan Museum, HYM, the vert collection being HYMV. This is
probably the wierdest name for an oviraptorosaur I've seen, sounding like
"hey, you..." but you take what you give, and there is a blessing ... it
doesn't end in -saurus.

  The holotype and four refered specimens are HYMV1-1--5, and are all
essentially on the same block and all probably even belong to the same
specimen. This is the same specimen as the Mandarin "duck" fossil with the
rather humorous anatomical referrences. In the slab, you can see some
possible soft tissue at the very end of the ischia, and this is what
probably led to the allusions of a "penis" in this critter. The specimen
is nearly complete, amazingly so for the snapshots of photo I have of it
otherwise, down to the nearly complete hands, feet, and skull. The last is
disarticulated, and the jaw is deformed, with the tail distal to the
seventh caudal missing. Two animals are preserved together, possibly
three: the first animal is represented by the type; another is represented
by partial legs and pubis (HYMV1-4) that are closely assosicated to the
type, in that they form a contiguous block when assembled; HYMV1-3 and 1-5
are both separated and represent a right manus and right arm,
respectively. The manus may belong to the type, as it lacks forelimb
material, but the right arm has a furcula, as does the type, and it does
not belong to the same animal.

  It comes from the Dalangshan Formation, which according to the Bureau of
Geology and Mineral Resources of Guangdong Province (1998, _Regional
Geology of Guangdong Province_ Ministry Geo. Min. Resoruces, Geo. Mem.
ser. 1, n. 9) is possibly of Maastrichtian in age. As an oviraptorid, this
just fits in nicely with the rest of the fossils.

  Its a pretty hefty animal: the ilium is estimated at 27.2 cm long, and
the femur is 22cm long, with an estimated femoral circumference of 106mm,
suggesting a weight of 54kg, or 119 lbs. Yeah. It was bigger than many
other oviraptorids....

  As for anatomy: The ilium and femur are remarkably like those of
*Conchoraptor* and GI 100/42, with a typical oviraptorid pubis, and an
ischium with a strongly ventrally pointing obturator process. The haemal
arches are very long proximally, and the sacra, caudals, as well as the
cervicals, all have pleurocoels; dorsals are not preserved well enough to
tell. The vertebral count is typical for oviraptorids, also: 13 cervicals,
an estimated 12 dorsals using a 25 presacral count, I assume, as it is
impossible to tell how many there actually are, supposedly 8 sacrals, and
seven or more preserved caudals, depending on how many are concealed
beneath the very long ilia. Lü counted eight sacrals, but I cannot see how
this number can be made as only two sacral centra are preserved very well,
the postacetabular ala is covering up the proximal tail and distal
sacrals, and the ilia are eroded down to show that underlying them all
that are present are portions of neural arch and sacral rib. Lü divides
the cervical and dorsal columns based on fusion of ribs in the cervicals
versus separate in the dorsals, but the figured first dorsal is clearly a
cervical in having a short, horizontal rib, and I would bet the next two
in the series were cervicodorsals; this gives a count of 14 cervicals, as
in GI 100/42, and *Neimongosaurus*, including the atlas.

  The arms are short, and resemble those of both *Ingenia* and
*Conchoraptor*, especially the latter, but the metacarpals and hand in
general is nearly identical to that of the former. Lü describes the manus
as being a carpometacarpus, and illustrates this in the ventral view of
the manus of HYMV1-2; however, it is clear from the dorsal view and the
photo of the arm and hand, that there is a distinct division between the
semilunate carpal and metacarpal I and II; in the ventral view, the
illustration shows that the semilunate and mcI are conjoined.

  The femur is shorter than the tibia by a fair deal, and the pes is a
fair deal shorter than the tibia; the proximal tarsals are not obvious,
and the cnemial crest was ventrally pointed and trapezoidal, almost
triangular in lateral view. The pes was big, as in *Conchoraptor*.

  Several ribs are well preserved, and none show uncinate processes
despite them being attached to proximal dorsals as demonstrated from
neural arch position and the presence of a dislocated dorsal that is
probably dv2 with non-uncinated rib attached.

  The cranium is crushed and almost completely broken up, with only the
rear fourth of the skull in any good condition, including quadrate,
postorbital, and quadratojugal; the rostral end of the cranium is present
as a shattered mess. The lower jaw is distorted, but implies a short, high
mandible, with a stronly decurved ventral margin, as in the lower jaw
referred to *Ingenia*. The dorsal margin of the jaw does not appear to be
as angular as in *Ingenia*, but is similar to *Citipati* and *Khaan*, as
well as *Oviraptor*.

  Most of the paper, fortunately, is made up of describing the animal.
However, Lü goes on to discuss the phylogenetics of *Heyuannia*. It is
diagnosed by the following features:

  1) increased cervical and sacral vertebral counts (as explained above,
there's nothing unique in *Heyuannia* about the neck and the sacral count
is equivocal);
  2) the articulating surface for the quadratojugal on the lateral distal
quadrate is a groove rather than a cotylar peduncle, as in other
oviraptorids;
  3) the quadratic diverticulum enters the quadrate anterolaterally,
appearing as a fenestra into the quadrate on the margin between quadratic
shaft and pterygoid flange;
  4) cervical neural arches and ribs have pneumatic foramina (the former
is known in *Chirostenotes* and *Microvenator*);
  5) pubis and ilium subequal (as in *Nomingia*);
  6) proximal end of metacarpal wraps that of metacarpal II in ventral
view (this is an expansion of the volar proximal process of the mcI that
braces mcII ventrally in other maniraptorans, and the only thing unique
here is that is covers the proximal end of mcII entirely in ventral view).

  Lü then goes on to describe *Heyuannia*'s place in the Avialae. "In
non-avian theropod dinosaurss," he writes, "there are fewer than 11
cervical veterbare, 12 dorsal vertebrae, and fewer than 8 sacral
vertebrae." However, this is erroneous; *Caudipteryx*, a non-avian
dinosaur, have a cervical count of 12, and *Neimongosaurus* which I bet
even Czerkas would balk at calling a bird, has a count of 14, as do
several other oviraptorosaurs. Similarly, acquisition of the dorsals into
cervicals with logically reduce the dorsal count, and if those
short-backed therizinosaurs have anything to say about it, this is
convergent. Lü also suggests that the grooved articulation between
quadrate and quadratojugal indicate possible cranial kinesis; the
postacetabular alae taper and the dorsal margin of the ilia are "gently
convex", the pneumatized cervical neural arches (as in most maniraptorans
and in *Gallimimus*, I might add, and *Thecocoelurus*), and the long tibia
relative to femoral length "strengthens support for the avialan status of
oviraptorosaurs."

  As Mickey Mortimer points out to me, one of the final statements in the
paper is "Recent phylogenetic analysis shows that oviraptorosaurs fall
within birds (Maryanska et al., 2002; Lü et al., 2002)" but fails to cite
Xu et al. (2002) or Hwang et al. (2001) who indicated a non-avian position
for a monophyletic Oviraptorosauria, whereas in Maryanska et al., the
assembly of oviraptorosaurs was polyphyletic relative to *Confuciusornis*
among other birds. These analyses have not met on any level, and the
analyses of Lü et al. and Maryanska et al. did not give a very large
selection of possible outgroups, but only one non-avian theropod,
*Velociraptor*.

  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)

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