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JVP 25(2): New Dinos, Birds, Discoveries




  My issue arrived today, so I can run off some quick summaries of the few
dino-paleo-related papers involved.

  First, the first dinosaur taxon from Hungary that is likely VALID:

  Osi, A. 2005. *Hungarosaurus tormai*, a new ankylosaur (Dinosauria) from the
Upper Cretaceous of Hungary. _JVP_ 25(2):370-383. {Osi is written with a double
acute above the "o", and is pronounced as "eh" as in "her".)

  Describes the new taxon based on an extensive holotype and three paratypes:
holotype, MTM Gyn/404 (premaxilla, left lachrymal, left prefrontal, right
postorbital, jugal and quadratojugal, left frontal, vomer, pterygoid, right
quadrate and part of left quadrate, basioccipital, one _in situ_ premaxillary
and 21 isolated teeth and one hyoid, portions of the anterior dentary,
surangular, angular, and a small fragment of posterior dentary; three
cervicals, six dorsals, ten caudals with three cervical and 13 dorsal ribs,
five chevrons and some tendon fragments; complete left scapulocoracoid and
right scapula portion of the adjoining coracoid, right radius and four
metacarpals; preacetabular fragments of both ilia, left ischium, right femur
and fibula, and ~100+ osteoderms); paratype, MTM Gyn/405 (anterior dorsal,
cervical and dorsal ribs, a single half-ring osteoderm [thus cervical], and
smaller circular osteoderms); paratype MTM Gyn/406 (fragmentary ulna, distal
?femur, a metapodial, fragmentary ribs, osteoderms); MTM Gyn/407 (sacrum with
sacral rod [four presacrals fused as preserved], fragmentary right and complete
left ilia, both ischia, isolated sacral with fused osteoderm).

  The animal is named for Hungary and Andráa Torma, friend of the author and
discoverer of the type locality. It derives from the Czehbánya Formation,
Santonia, Upper Cretaceous less than 1km east of Iharkút, Veszprém County,
Hungary, in the Bakony Mts of the Transdanubian Range.

  It is diagnosed thusly (my comments in brackets): "Armored dinosaur,
approximately 4m long; large notch at front of premaxillae [compare to
*Gastonia* and *Cedarosaurus*], thin nasal process of premaxillae, robust
rhomboidal quadrate condyles, large interpterygoid vacuity, dorsoventrally wide
quadratojugal with strong protuberance, posterodorsally oriented crest-like
protuberance on postorbital, short diastema between symphysis and first dentary
tooth position, very short retroarticular process of surangular, anterior-most
dorsal vertebra with unusual transversely wide, anteroposteriorly short
amphycoelous [sic] centrum, with very large neural canal, dorsally displaced
pseudoacromial process of scapula."

  *Hungarosaurus* was included in the analysis of Vickaryous et al., from _the
Dinosauria, 2nd Ed._, with 63 characters (41 of which are cranial) and 17 taxa,
for a pair of analyses; the first was a concensus of 6 trees placing
*Hungarosaurus* in a polytomy with various nodosaurids, collapsing Ankylosaurs
more advanced than the outgroup *Scelidosaurus* but retaining ankylosaurid
monophyly anmd structure and *Edmontonia* and *Panoplosaurus* were sister taxa
(big surprise there....). The second analysis was restricted to cranial
characters and places *Hungarosaurus* as a nodosaurid more advanced than
*Struthiosaurus* but less derived than edmontoniines or sauropeltines, and
*Pawpawsaurus* is a basal edmontoniine; *Minmi* is an ankylosaurid more
advanced than *Gargoyleosaurus*.

  --

  Louchart, A., P. Vignaus, A. Likius, H. T. Mackaye and M. Brunet. 2005. A new
swan (Aves: Anatidae) in Africa, from the latest Miocene of Chad and Libya.
_JVP_ 25(2):384-392.

  Describes a humerus as the holotype (TM112.00.196) of a new genus and species
of African swan, *Afrocygnus chauvireae*, in honor of Cécile Mourer-Chauviré.
It derives from the Miocene beds of Toros Menalla, which is also yielding
important clues to hominid origins, in the Anthracotheriid Unit of Vignaud et
al. 2002 (dated around 7 Ma). The humerus is complete and appears to represent
a distinct cygnin (member of "subtribe" Cygnina, "tribe" Cygnini, "subfamily"
Anserinae, which includes only *Cygnus* of all swan genera). The authors
speculate that the taxon may be either a sister taxon to *Cygnus*, or within a
paraphyletic association of *Cygnus* subgenera (*Chenopis*, *Cygnus* and
*Olor*).

  --

  Yates, A. and C. C. Vasconcelos. 2005. Furcula-like clavicles in the
prosauropod dinosaur *Massospondylus*. _JVP_ 25(2):466-468.

  Yates and Vasconcelos described the the clavicles of a specimen of
*Massospondylus* (BP/1/5241) from a farm in the Barkly East District of Eastern
Cape, South Africa (Farm Upper Drombo), deriving from the upper Elliot
Formation, Karoo Supergroup, and Hettangian or Sinemurian in age, Early
Jurassic. Two long paried bones lie above the acromia of the scapula and above
the dorsal margins of the coracoids and adjoin one another in a V-shape of
nearly perfectly 90 degrees. One end overlaps the other slightly, and the
shafts are slightly arched along their lengths; striae at the distal ends imply
soft-tissue interaction as tendons binding the distal ends of the rods.
Articulation of the scapulae are nearly vertical; though this may be slightly
motivated from their original position, articulation of the clavicles imply
such movement was minor indeed. The authors go on to mention previous reports
of "prosauropod" clavicles, including *Plateosaurus* and *Massospondylus*, but
mention that in the latter, SAM 5153 probably represents a sternal plate; four
*Plateosaurus* have been reported with clavicles, though only one specimen
(SMNS 58958) remains to preserved them whereas the others (GPIT skelett 1 & 2,
AMNH 6810) have had the elements obliterated. These specimens show that the
position of the elements were either moved, or never recorded, thus their
articulation is in question. The authors profer the only model rendered of the
accesory skeleton in this region, Paul, 1987, and reconstruct the clavicles
well separated from Paul's inferred episternum, which are omitted based on lack
of evidence. This suggests that saurischians may have possessed articulated
V-shaped clavicles ancestrally, and it may also afford that reports of
*Segisaurus* and *Coelophysis* clavicles may not form fused furculae, but only
articulate as V's given the lack of preservation at the median.

  --

  Sampson, S. D. and M. A. Loewen. 2005. *Tyrannosaurus rex* from the Upper
Cretaceous (Maastrichtian) North Horn Formation of Utah: Biogeographic and
paleoecologic implications. _JVP_ 25(2):469-472.

  The authors described the partial skeleton (UMNH 11000) of *Tyrannosaurus
rex* from Utah's North Horn Fm of Emery County, Utah, at the type locality of
North Horn Mtn. The specimen is 17% complete with only portions of posterior
skull bits including a complete squamosal and postorbital (_sans_ a portion
connecting them less than 2 cm wide), several cervical, sacral and caudal
vertebrae, chevrons, pelvic fragments, as well as the left tibia, fibula, and
astagalus. UMNH 11000 is referred to *T. rex* on the basis of a nearly right
angle between the squamosal and jugal rami of the postorbital, a subcircular
shape to the cornual process of the postorbital, and similarities in the
squamosal including an elongate, broad quadratojugal ramus, a deep incision for
reception of the postorbital, and a broad pneumatic excavation in the corpus.
The specimen also affords the first direct association between *Tyrannosaurus*
and *Alamosaurus*.

  Detail is offered on the associations of specimens that provide some
biogeographic data, but not correlated with time. *Alamosaurus* and
*Torosaurus* dominate intermontane basins (which did not extend further north
than northern Wyoming, and *Alamosaurus* is no further north than SW Wyoming),
while *Triceratops* and *Edmontosaurus* dominate the coastal plain, with
*Leptoceratops*, hadrosaurids, and ankylosaurids dominate the central alluvial
plain (which did not extend further south than central Wyoming).
*Tyrannosaurus* specimens appear to prefer the coastal plain and occasionally
appear to lead into the intermontane regions, arguing preferrence of occurence
(bias?) for the coastal plaine. This suggests that *Alamosaurus* association
may not neccessarily have had much of an effect on *Tyrannosaurus* evolution.
However, the authors conclude by arguing that *Tyrannoaurus* was an ecological
generalist, and this appears to have been the conclusion of all but a very few;
preference for ceratopsid and/or hadrosaurid prey have dominated the occurences
as well as associations of tyrants and food.

  --

  In addition,   Goswami et al. describe dental microwear in Triassic amniotes
in order to infer diets. They included dentition from the Triassic Isalo II
fauna, of cynodonts, traversodonts, and the "prosauropods" mentioned by Flynn
et al. in 1999 and now potentially, with the discovery of *Silesaurus* perhaps
a tad bit more basal than dinosaur. Tooth microwear length and orientation are
studied, and Kruskall-Wallis tests are applied. The teeth appear to have been
engaging with plants. Mechanics developed from the teeth imply that the jaw
moved posterodorsally as it closed, reaffirming Crompton's 1972 model for
traversodont feeding. Meanwhile, the "prosauropod" teeth show virtually
completely orthal movements (dorsoventral scratches without much deviation), in
direct contrast to later dinosaur jaw specialization showing complex and
delicate jaw movements during feeding.

  Farlow et al. describe a method for estimating body size based on femur size
using *Alligator* as a model, and applications to other crocodylians. Estimates
of interest include 7.2-9.1m for *Sarcosuchus* and 10.6m for *Deinosuchus*.

  Company et al. describe a new species of ziphodont croc (the group that
includes notosuchians and *Sebecosuchus*) from Valencia, Spain, *Doratodon
ibericus,* from a jaw much more robust and shorter than the type species, *D.
carcharidens*. Most peculiar are the teeth which, when seen in detail, are
triangular, some with minimal curvature, some nearly symmetrical and others
curved on the distal carina; all have fine, rounded and distinct
denticulations, no keels, no basal constriction of the crown and root, and
smooth enamel without any striae or flexures that characterize some
psuedoziphodont croc teeth (including a "festooned" carina formed from wrinkles
in the enamel immitating denticular serrae). The animal is another example of
convergent dentition, and the previous taxa with similar teeth include
*Ricardoestesia* and *Revueltosaurus*. The jaw appears to have resembled
*Araripesuchus* and *Baurusuchus* somewhat in profile, including a likely large
external mandibular fenestra.

  Several papers on ichthyosaurs include the description of ichthyosaurid
prefrontals from Motani, discussion of *Caypullisaurus* sclerotic ring function
and structure from Fernández et al., and Motani's note on *Mixosaurus*
durophagy; mosasaurs are also well-featured including a new skull of
*Taniwhasaurus* from Caldwell et al., and K/T mosasaurs from Missouri by
Gallagher et al.

  Cheers,

Jaime A. Headden

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


                
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