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Knoll, F., Padian, K., and de Ricqles, A. 2009. Ontogenetic change and adult
body size of the early ornithischian dinosaur Lesothosaurus diagnosticus:
Implications for basal ornithischian taxonomy. Gondwana Research. doi:
10.1016/j.gr.2009.03.010.

ABSTRACT: Questions about the taxonomic status, diversity, and pace of
evolution of basal ornithischian dinosaurs persist in part because some
historically important taxa have been based on incomplete material of
uncertain ontogenetic status. We examined the morphology of critical
?fabrosaurid? specimens and analyzed the bone tissues of small and large
individuals. We conclude that the case for the existence of a
non-heterodontosaurid ornithischian distinct from Lesothosaurus diagnosticus
in the upper Elliot Formation of southern Africa is not conclusive and we
suggest that this species and Stormbergia dangershoeki may actually
represent ontogenetic stages of one taxon that reached maturity in
approximately four years.



Fujiwara, S.-I. 2009. Olecranon orientation as an indicator of elbow joint
angle in the stance phase, and estimation of forelimb posture in extinct
quadruped animals. Journal of Morphology. doi: 10.1002/jmor.10748.

ABSTRACT: Reconstruction of limb posture is a challenging task in assessing
functional morphology and biomechanics of extinct tetrapods, mainly because
of the wide range of motions possible at each limb joint and because of our
poor knowledge of the relationship between posture and musculoskeletal
structure, even in the extant taxa. This is especially true for extinct
mammals such as the desmostylian taxa Desmostylus and Paleoparadoxia. This
study presents a procedure that how the elbow joint angles of extinct
quadruped mammals can be inferred from osteological characteristics. A
survey of 67 dried skeletons and 113 step cycles of 32 extant genera,
representing 25 families and 13 orders, showed that the olecranon of the
ulna and the shaft of the humerus were oriented approximately perpendicular
to each other during the stance phase. At this angle, the major extensor
muscles maximize their torque at the elbow joint. Based on this survey, I
suggest that olecranon orientation can be used for inferring the elbow joint
angles of quadruped mammals with prominent olecranons, regardless of taxon,
body size, and locomotor guild. By estimating the elbow joint angle, it is
inferred that Desmostylus would have had more upright forelimbs than
Paleoparadoxia, because their elbow joint angles during the stance phase
were approximately 165° and 130°, respectively. Difference in elbow joint
angles between these two genera suggests possible differences in stance and
gait of these two mammals.



Fujiwara, S.-I., Kuwazuru, O., Inuzuka, N., and Yochikawa, N. 2009.
Relationship between scapular position and structural strength of rib cage
in quadruped animals. Journal of Morphology. doi: 10.1002/jmor.10744.

ABSTRACT: Determining scapular position is a major issue in reconstructing
the skeletal systems of extinct quadruped archosaurs and mammals, because
the proximal portion of the scapulae has no direct skeletal joint with the
vertebrae or ribs. When quadrupeds stand or walk, their trunk is suspended
between the forelimbs by the serratus muscles, which arises from the lateral
sides of the thoracic ribs and inserts into the proximal portion of the
costal surface of the scapula. Therefore, the thoracic ribs are subjected to
a static or dynamic vertical compression between the lifting force from the
muscle and the gravitational force from the vertebral column. To investigate
the body support function of the ribs, we analyzed the mechanical strength
of the ribs of extant tetrapods by the two-dimensional finite element
method, and compared the degree of strength through their craniocaudal
scapular positions. The result of this simulation showed that the thoracic
ribs of quadrupeds, to which the serratus muscles attach, have a relatively
higher strength against compaction than the other ribs. In bipeds, however,
we did not find a similar correlation between the strength of ribs and the
serratus muscle. This implies that the location of robust ribs is associated
with the arrangement of the serratus muscle, and provides a probable
candidate for determination of the scapular position for extinct quadruped
archosaurs and mammals.




Mitchell, G., van Sittert, S.J., and Skinner, J.D. 2009. Sexual selection is
not the origin of long necks in giraffes. Journal of Zoology. doi:
10.1111/j.1469-7998.2009.00573.x.

ABSTRACT: The evolutionary origin of the long neck of giraffes is enigmatic.
One theory (the 'sexual selection' theory) is that their shape evolved
because males use their necks and heads to achieve sexual dominance. Support
for this theory would be that males invest more in neck and head growth than
do females. We have investigated this hypothesis in 17 male and 21 female
giraffes with body masses ranging from juvenile to mature animals, by
measuring head mass, neck mass, neck and leg length and the neck length to
leg length ratio. We found no significant differences in any of these
dimensions between males and females of the same mass, although mature
males, whose body mass is significantly (50%) greater than that of mature
females, do have significantly heavier (but not longer) necks and heavier
heads than mature females. We conclude that morphological differences
between males and females are minimal, that differences that do exist can be
accounted for by the larger final mass of males and that sexual selection is
not the origin of a long neck in giraffes.




Kundrat, M., Janacek, J., and Martin, S. 2009. Development of transient head
cavities during early organogenesis of the Nile Crocodile (Crocodylus
niloticus). Journal of Morphology. doi: 10.1002/jmor.10743.

ABSTRACT: Three consecutive pairs of head cavities (premandibular,
mandibular, and hyoid) found in elasmobranchs have been considered as
remnants of preotic head somites - serial homologues of the myotomic
compartments of trunk somites that give rise to the extraoccular
musculature. Here, we study a more derived vertebrate, and show that
cavitation is more complex in the head of Crocodylus niloticus, than just
the occurrence of three pairs of cavities. Apart from the premandibular
cavities, paired satellite microcavities, and unpaired extrapremandibular
microcavities are recognized in the prechordal region as well. We observed
that several developmental phenomena occur at the same time as the formation
of the head cavities (premandibular, satellite, extrapremandibular,
mandibular, and hyoid) appear temporarily in the crocodile embryo. These are
1) rapid growth of the optic stalk and inflation of the optic vesicle; 2)
release of the intimate topographical relationships between the neural tube,
notochord and oral gut; 3) tendency of the prechordal mesenchyme to follow
the curvature of the forebrain; and 4) proliferation of the prechordal
mesenchyme. On the basis of volumetric characters, only the hyoid cavity and
hyoid condensation is comparable to the trunk somitocoel and somite,
respectively.



Lockley, M., Chin, K., Houck, K., Matsukawa, M., and Kukihara, R. 2009. New
interpretations of Ignotornis, the first-reported Mesozoic avian footprints:
implications for the paleoecology and behavior of an enigmatic Cretaceous
bird. Cretaceous Research. doi: 10.1016/j.cretres.2009.04.001.

ABSTRACT: The type material of Ignotornis mcconnelli, the first reported
Mesozoic bird track, consists of a large, monospecific sample of ~70
footprints comprising at least 15 recognizable trackways. However, the exact
type horizon and locality, discovered in 1930 in the Cretaceous Dakota Group
near Golden, Colorado, was not indicated in the original 1931 description by
Maurice Mehl, and only the single holotype trackway was illustrated. In
1988, the known sample was doubled by the discovery of ~70 additional tracks
representing at least seven trackways, but again the exact type horizon and
locality remained uncertain. In 2007, we discovered what we infer to be the
original type locality, and identified approximately 150 additional
footprints comprising at least 17 additional trackways. During the study we
also located three more specimens, in other collections, comprising at least
60 tracks and 10 trackways. Thus, the type (holotype, paratype, and
topotype) sample now consists of ~360 footprints comprising about 50
trackways, of which 41 have been measured. Although most footprints from the
1930, 1988, and 2007 finds all appear to originate from the same ?type?'
horizon associated with a volcanic ash, a few tracks were found in 2007 at
two additional levels.
     The relatively long, reversed hallux and the incipient semi-palmate
webbing in the hypex between digits III and IV make Ignotornis distinct from
any other Cretaceous bird tracks known from North America. These features,
used to infer the extant forms with which Ignotornis is most convergent, are
reminiscent of small herons, and unlike the typical tracks of most
Cretaceous shorebird-like species which resemble those of plovers and
sandpipers. Clearly defined parallel and sub parallel trackways indicate
gregarious behavior, while some trackways indicate unusual ?shuffling? and
?stop-start? progression, probably related to some type of ?foot-stirring?
foraging activity. The concentration of abundant Ignotornis tracks at a
single locality within the ichnologically-famous ?Dinosaur Freeway?
(represented by more than 60 dinosaur and crocodile dominated track
assemblages) suggests that the Ignotornis track maker was a ?rare-bird? in
the region during the Cretaceous.



Lü, J. 2009. A new non-pterodactyloid pterosaur from Qinglong County, Hebei
Province of China. Acta Geologica Sinica (English Edition) 83(2):189-199.
doi: 10.1111/j.1755-6724.2009.00062.x.

ABSTRACT: A new basal non-pterodactyloid pterosaur, Changchengopterus pani
gen. et sp. nov., is erected, on the basis of a nearly complete postcranial
skeleton. The new taxon is distinguished by relatively short extensions of
the prezygapophyses, postzygapophyses and haemal arches of the caudal
vertebrae; a humerus that has a subtriangular deltopectoral crest; limb
elements that decrease in length in the following order: ulna> wing-phalange
2 > wing-phalange 3 = wing-phalange 1>humerus >tibia>femur>wing-metacarpal.
Phylogenetic analysis suggests that Changchengopterus is a basal member of
rhamphorhynchoids, and more closely related to Dorygnathus than to other
rhamphorhychoids. The geological age of the Changchengopterus-bearing
sediments is no latter than the end of the Late Jurassic and it is possible
Middle Jurassic.

     (just so no one gets confused by this: it's not from the Jehol Group,
but another unit called the Tiaojishan Formation.)



Jin, L., Chen, J., Zan, S., and Godefroit, P. 2009. A new basal
neoceratopsian dinosaur from the Middle Cretaceous of Jilin Province, China.
Acta Geologica Sinica (English Edition) 83(2):200-206. doi:
10.1111/j.1755-6724.2009.00023.x.

ABSTRACT: A new basal neoceratopsian dinosaur, Helioceratops brachygnathus
gen. et sp. nov., is described from the Quantou Formation (late Early
Cretaceous or early Late Cretaceous) in the Liufangzi locality (Jilin
province, China). Helioceratops differs from other basal neoceratopsians
with its deep dentary ramus, its steeply-inclined ventral predentary facet,
its heterogeneous dentary crowns, and by the denticles and secondary ridges
asymmetrically distributed on either side of the primary ridge on its
dentary teeth. Along with Auroraceratops and Yamaceratops, Helioceratops
represents one of the most derived non-coronosaurian neoceratopsians. The
palaeogeographical distribution of basal neoceratopsians appears limited to
northern China and southern Mongolia in the current state of our knowledge.
It is therefore probable that this region constituted the birthplace for
more advanced, Late Cretaceous Coronosauria.



Jin, L., Chen, J., Zan, S., and Godefroit, P. 2009. A new basal
neoceratopsian dinosaur from the Middle Cretaceous of Jilin Province, China.
Acta Geologica Sinica (English Edition) 83(2):200-206. doi:
10.1111/j.1755-6724.2009.00023.x.

ABSTRACT: A new basal neoceratopsian dinosaur, Helioceratops brachygnathus
gen. et sp. nov., is described from the Quantou Formation (late Early
Cretaceous or early Late Cretaceous) in the Liufangzi locality (Jilin
province, China). Helioceratops differs from other basal neoceratopsians
with its deep dentary ramus, its steeply-inclined ventral predentary facet,
its heterogeneous dentary crowns, and by the denticles and secondary ridges
asymmetrically distributed on either side of the primary ridge on its
dentary teeth. Along with Auroraceratops and Yamaceratops, Helioceratops
represents one of the most derived non-coronosaurian neoceratopsians. The
palaeogeographical distribution of basal neoceratopsians appears limited to
northern China and southern Mongolia in the current state of our knowledge.
It is therefore probable that this region constituted the birthplace for
more advanced, Late Cretaceous Coronosauria.



Zhang, X., Lü, J., Xu, L., Li, J., Yang, L.K., Hu, W., Jia, S., Ji, Q., and
Zhang, C. 2009. A new sauropod dinosaur from the Late Cretaceous Gaogou
Formation of Nanyang, Henan Province. Acta Geologica Sinica (English
Edition) 83(2):212-221. doi: 10.1111/j.1755-6724.2009.00032.x.

ABSTRACT: A new sauropod dinosaur Baotianmansaurus henanensis gen. et sp.
nov. from the Cretaceous Gaogou Formation of Neixiang, Henan Province is
erected. It is characterized by somphospondylous presacral vertebrae; a
highly-developed lamina system on the dorsal vertebrae; transverse process
supported by four laminae; and the dorsal portion of the anterior
centroparapophyseal lamina is bifurcated, with a small branch extending to
the ventral surface of the prezygapophysis. It represents a new
titanosauriform sauropod.




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
 and     dinogami@gmail.com
http://cactus.dixie.edu/jharris/

"Life is the art of drawing
sufficient conclusions from
insufficient premises."
               -- Samuel Butler