Mesozoic Vertebrate Life: Sauropods and Ornithischians

["Jaime A. Headden" <qilongia@yahoo.com>]

Tanke, D.H. & Carpenter, K. (eds.); Skrepnick, M.W. (art ed.)
2001. _Mesozoic Vertebrate Life: New Research Inspired by the
Paleontology of Philip J. Currie_. Indiana University Press
(Bloomington & Indianapolis [Indiana]) 577 pp.

Part II, Sauropods and Ornithischians.

  Surprisingly, not a lot of papers, but hey, you get what you
can.

11 ---

Tidwell, V.; Carpenter, K.; & Meyer, S. 2001. New
titanosauriform (Sauropoda) from the Poison Strip Member of the
Cedar Mountain Formation (Lower Cretaceous), Utah. p. 139-165.

  Describes *Venenosaurus dicrocei,* and thankfully more
complete than even *Cedarosaurus* is ... stats are as follows
(as in the last installment, anything in corner brackets " [ ] "
are my own comments unless otherwise indicated):

--  Holotype: DMNH 40932, nine disarticulated caudal vertebrae,
a left scapula and ulna, right radius and all five metacarpals
(distal 2/3 of mcI missing), and the phalanges to go with it or
the other manus; both ischia but only the right pubis, three
metatarsals, an astragalus, several chevrons, and ribs. Closed
neurocentral sutures suggest and adult age, but the lack of a
scapulocoracoid fusion or closure of the coracoid foramen make
this questionable; thus, I would call it a young adult at best.
  Measurements are as follows: caudals, length/relative
posterior centrum height/total height -- proximal,
112mm/166mm/420mm; anterior, 80mm/155mm/unknown; mid,
102mm/99mm/362mm; and distal vertebrae 101mm/49mm/unknown.
Scapula length/width behind the acromion - 1200mm/510mm (not
complete); radius length/least circumference - 695mm/235mm; ulna
length/least circumference - 768mm/266mm; pubis length - 652mm;
ischia (left/right) length - 592mm/581mm; metacarpal lengths
I/II/III/IV/V - broken/358mm/360mm/333mm/301mm, width of
metatarsus at greatest bredth (mcI to mcIV) - 209mm; metatarsal
lengths I/II/III - 136mm/169mm/178mm.
--  Horizon: Cedar Mountain Formation, in the Poison Strip
Sandstone Member, roughly Barremian in age. The type was located
in Grand County, Utah, at Tony's Bone Bed about 13 km due north
of Moab.
--  Diagnosis: This requires having some knowledge of the
various disarticulate basal titanosauriforms that have been
commonly lumped together as the Brachiosauridae or allied. There
appears to be a good deal of plasticity in caudal morphology of
such animals, and this has been the primary problem in relating
these animals one to the other; similarly, it doesn't help that
several are based on subadult or juvenile types. Tidwell et al.
(2001) provide the following features: caudals procoelous but
caudally flat, neaural spines inclined cranially, as imn
*Cedarosaurus* and *Aeolosaurus* [and *Andesaurus*], mid-caudals
amphiplatyan (see *Brachiosaurus*); pleurocoels extensive to the
mid-caudals; radius very slender (but not as much as
*Cedarosaurus*), and the ulna is nearly identical to
*Cedarosaurus* and titanosaurs in having a flat medial wall and
a well-defined medial process; the olecranon is only moderately
developed, the ulna is gracile with concave medial and caudal
margins; metacarpal I is flat proximally in the tight U-shaped
manus arrangement, much more slender than in other sauropods;
pubis is longer than the ischium, and only the proximal half of
the pubis bears a contact for the ischium; ribs with proximal
fossa and pockets invading capitulum.
--  Etymology: *Venenosaurus* > _venenos_ (Lat.) poison, in
reference to the Poison Strip SS Mbr. + _-saurus_ > _sauros_
(Grk.) lizard, reptile = "poison lizard"; _dicrocei_, in honor
of Anthony DiCroce, discoverer of the type. "DiCroce's Poison
[Strip SS] lizard."
--  Discussion: Features of the caudal verebrae suggest that
*Venenosaurus* is closer to titanosaurs than is *Brachiosaurus*,
but that *Venenosaurus* is very similar to *Cedarosaurus*,
*Andesaurus*, and other such very basal titanosaurs. The
position is uncertain given the need for adult *Pleurocoelous*
material and an understanding of caudal transformation in
titanosauriforms. Another specimen from the locality, collected
by Langston and Pittman (TMM 42488) is a collection of elements,
several shared by *Venenosaurus*, but not congruous in
morphology.

12 ---

Sanders, F.; Manley, K.; & Carpenter, K. 2001. Gastroliths from
the Lower Cretaceous sauropod *Cedarosaurus weiskopfae*. p.
166-180.

  The type of *Cedarosaurus* was found with gastroliths. These
are described, and include 115 separate clasts, ranging between
.04cc to 270cc [cc is cubic centimeters for those wondering].
Most clasts are less than 10cc, comprised of chert or quartzite,
but also a few of sand- and siltstone. This is a strait forward
analysis of gastrolith study, and provides methods in which to
study and analyze other clasts to test for being gastroliths;
these are.

13 ---

DiCroce, T. & Carpenter, K. 2001. New ornithopod from the Cedar
Mountain Formation (Lower Cretaceous) of eastern Utah. p.
183-196.

  Here is described the first iguanodont from the Cedar Mountain
formation, thankfully without a -saurus suffix ... :) ...
*Planicoxa venenica*. This is not the sail-backed iguanodont
previously reported.

--  Holotype: DMNH 42504, a complete left ilium.
--  Paratypes: DMNH 42511, cervical neural arch, lacking left
zygapophyses and diapophyses, and neural pedicel. DMNH 42516,
dorsal neural arch. DMNH 42518-42522, dorsal neural arches. DMNH
42524, dorsal neural arch. DMNH 42513, dorsal centrum. DMNH
42515, dorsal centrum. DMNH 42525, dorsal centrum. DMNH 42523,
dorsal rib fragment. DMNH 42526-42527, two dorsal rib fragments.
DMNH 42510, sacral vertebra. DMNH 42514, caudal centrum. DMNH
42517, caudal centrum. DMNH 42508, proximal end of the left
humerus. DMNH 42507, left ulna. DMNH 42505, left femur. DMNH
40917, right femur. DMNH 40914, right tibia. DMNH 40918, right
tibia. DMNH 42506, distal end of a left tibia. DMNH 42509, left
metatarsal II. DMNH 42512, pedal phalanx.
  Measurements are as follows: ilium, length - 354.3mm; femur,
length - 520-445mm; tibia, length - 445-480mm; ulna, length -
230mm. Elements occur in a bone bed [and are comprised by more
than one individual, based on two right tibiae].
--  Horizon: Cedar Mountain Formation, in the Poison Strip
Sandstone Member, roughly Barremian in age. The type was located
in Grand County, Utah, at Tony's Bone Bed about 13 km due north
of Moab.
--  Diagnosis: caudal centra bear paired ventral ridges,
connected cranial and distal chevron facets; humeral head
extends onto the anterior surface of the proximal end;
postacetabular blade lateral inflection horizontal, not
ventrally declined (as in stegosaurs); no cervical neural
spines, a feature seen in more gracile hadrosaurs.
--  Etymology: *Planicoxa* > _planis_ (Lat.) flat, level +
_coxa_ (Lat.) feminine, hip = "flat hip;" *venenica* >
_venenica_ (Lat.) feminine form of _venenicus_ derived from
poison, genitive of _venenos_, poison, in reference to the
horizon of recovery.  The name is implicitly feminine. "Poison
[Strip SS] flat hip."
--  Discussion: an iguanodont that can distinguished from
contemporaneous *Iguanodon lakotaensis* by the form of the
ilium, and caudals. It can be distinguished from *Tenontosaurus*
by the form of the ilium, hindlimb, humerus, and vertebrae.

14 ---

Brill, K. & Carpenter, K. 2001. A baby ornithopod from the
Morrison Formation of Garden Park, Colorado. p. 197-205.

  Brill and Carpenter described a probable juvenile
hypsilophodont skeleton of what could be *Othneilia* from the
Morrison of Garden Park, Fremont County, Colorado. The specimen
(DMNH 21716) consists of portions of the skull (frontals and a
left postfrontal), the caudalmost 3 neck vertebrae and all
dorsals, most of the sacrum, two caudal centra, the left
humerus, several ribs, the right femur and tibia, and two
phalanges presumably from the third digit of the right foot.
Unfused neurocentral sutures  and spongy epiphyses of the bones
indicate the animal was probably a juvenile. The humerus is
strait, unlike the type of *Othneilia rex*, but despite the
authors, the form of the cranial remains cannot be compared to
*Othneilia* in the abscence of secure data regarding the skull.
The femur is 79mm long, the tibia ~85 estimated, and humerus
53mm estimated.

15 ---

Tanke, D.H. & Brett-Surman, M.K. 2001. Evidence of hatchling-
and nestling-size hadrosaurs (Reptilia: Ornithischia) from
Dinosaur Provincial Park (Dinosaur Park Formation: Campanian),
Alberta. p. 206-218.

  Eggshell and bones of just-hatched or developing infants are
described, found in strata located as a lowland environment,
unlike the Two Medicine collection. These remains are extensive,
and the paper includes an appendix indexing them.

16 ---

Pasch, A.D. & May, K.C. 2001. Taphonomy and paleoenvironment of
a hadrosaur (Dinosauria) from the Matanuska Formation (Turonian)
in south-central Alaska. p. 219-236.

  A bonebed in the Talkeetna Mountains of Alaska, Matanuska
Formation, yields the remains (>70 elements or portions of
elements) of a hadrosaur (AK 2000 P-02). The strata is primarily
a mudstone with marine inclusions, including calcareous
concretions and pyrite crystals. Surfaces also indicate
wave-rippled substrate. The prescence of the Japanese
heteromorph mid-Turonian ammonite *Muramotoceras* provides a
dating for the Matanuska. The listing of elements recovered
appear to pertain to the same individual, despite lack of
articulation and wheather and bioturbation. Most regions of the
skeleton are known to the exclusion of the head, neck, left
tibia/fibula, sacrum, and most ribs. The specimen is referred to
the Hadrosauridae, and in comparison to specimens of
*Edmontosaurus*, the caudal centra are longer but the limb
material roughly comparative.

17 ---

Zhiming D. 2001. Primitive armored dinosaur from the Lufeng
Basin, China. p. 237-242.

  Describes the new "scelidosaurid" *Bienosaurus lufengensis*
from the Lower Lufeng Formation ... China (duh...).

--  Holotype: IVPP V9612, most of the right dentary with much of
the predentary attached bearing nine teeth and spaces for >3 or
more, a frontal (right?), a possible pterygoid and maxilla, and
other scute-like elements, and a possible supraorbital. [Many
elements labelled here as pertaining to portions of the skull
may very well be dermal ossicles.]
  The jaw measures 57.4mm without the predentary, and may have
extended a further 10mm caudally to the coronoid eminence. The
tallest tooth measures 8.4mm above the dentigerous margin, but
is well worn; a better tooth with complete margins and
serrations is 6.1mm high.
--  Horizon: The Lower Lufeng Formation, in the Dark Red Beds,
of the Lufeng Basin, Yunnan Province, China.
--  Diagnosis: Short and wide predentary; "frontal" thick and
with dorsal scutes fused to surface; dentary very wide, the
lateral surface of which is ornamented [ripple-like ridges
running at an angle rostrodorsally to caudoventrally]; teeth
phyllodont and bearing a slight cingulum on all teeth caudal to
the first two, which are semi-conical and recurved.
--  Etymology: *Bienosaurus* > Bien [M.N. Bien, collector of the
material] + _-saurus_ (Lat.) > _sauros_ (Grk.) lizard, reptile.
= "Bien's lizard." *lufengensis* > Lufeng, locality of
collection + _-ensis_ (Lat.) locative genetive suffix. "Bien's
lizard from the Lufeng [Formation or Basin]."
--  Discussion: Following Romer (1968) and Olshevsky (1991),
Dong has *Scelidosaurus* in the Ankylosauria as a basal family.
On the basis of the form of the crowns, this animal is a
thyreophoran, and the lateral ornamentation certainly suggests
it is a basal ankylosaur. [No features unite *Scelidosaurus* and
*Bienosaurus*, and Dong's justification is based on the basal
position and content of Cope's taxon Scelidosauridae, including
*Lusitanosaurus*, *Emausaurus*, *Scutellosaurus*, and
*Scelidosaurus*. Carpenter's forthcoming analysis is not cited,
unfortunately, and Dong follows the classic method of using
Scelidosauridae as a wastebasket. My recommendation is that this
animal is Ankylosauria _incertae sedis_.]

18 ---

Makovicky, P.J. 2001. A *Montanoceratops cerorhynchus*
(Dinosauria: Ceratopsia) braincase from the Horseshoe Canyon
Formation of Alberta. p. 243-262.

  A braincase referrable to *Montanoceratops cerorhynchus* is
from the Horseshoe Canyon Formation, Alberta, collected in 1910
and housed in the AMNH (AMNH 5244). This specimen comprises the
occipital plate, portions of fused parietals, both
laterosphenoids, and the basisphenoid. I don't want to sit here
and redescribe the specimen for Makovicky. However, a short
piece: it is the first non-ceratopsian neoceratopsian braincase
found in the Horseshoe Canyon Formation. Placing the braincase
in a matrix, Makovicky produces a phylogeny with some
interesting results:

--+--Hypsilophodon foxi [sic = foxii]
  `--Marginocephalia
     |--Stegoceras validus [sic = validum]
     `--Ceratopsia
        |--Chaoyangsaurus youngi
        `--+--Psittacosaurus mongoliensis
           `--Neoceratopsia
              |--Archaeoceratops oshimai
              `--+--Leptoceratopsidae
                 |  |--Asiaceratops salsopaludalis
                 |  `--+--Montanoceratops cerorhynchus
                 |     `--+--Leptoceratops gracilis
                 |        `--Udanoceratops tschizhovi
                 `--Coronosauria
                    |--Microceratops gobiensis [Sereno's
Graciliceratops]
                    `--+--Protoceratopsidae
                       |  |--Bagaceratops rozhdestvenskyi
                       |  `--Protoceratops andrewsi
                       `--Ceratopsoidea
                          |--Zuniceratops christopheri
                          `--Ceratopsidae
                             |--Centrosaurus apertus
                             `--Triceratops horridus

  This phylogeny differs significantly from that offered by Zhao
et al., 2000 and Sereno's 1998 or 1999 phylogenies (essentially
the same thing). Data on the stats for the analysis are not
published, so I'd need to run it to get these. Needless to say,
out of 98 characters whose goal is to resolve non-ceratopsid
relationships, is a good matrix, but some species
(*Turanoceratops* and *Breviceratops*) are conspicuously absent.

19 ---

Sampson, S.D. 2001. Speculations on the socioecology of
ceratopsid dinosaurs (Ornithischia: Neoceratopsia). p. 263-276.

  Here's an ecology piece on the similarity and dissimilarity of
ceratopsids to ungulate mammals. This is the official paper on
horns and frills being dynamically agonistic and intraspecific
in function, rather than defensive or offensive. Several factors
including the often errant explorations of lone female bovids in
selecting for large, male style horns; sexual selection and
dimorphism; gregariousness (herding behavior); environment and
habitat; retarded sexual development; and predation pressure are
considered in light of defining how to look at ceratopsid horns
and frills. In other words, ceratopsids are really like large
bovids and similar artiodactyls in their apparent ecology and
taphonomy inferences, suggesting....

Next, Paleoenvironments, Faunas, Paleopathology, and Ichnology....

=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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