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The Burning New Papers
Royo-Torres, R., Cobos, A., Luque, L., Aberasturi, A., Espílez, E., Fierro,
I., González, A., Mampel, L., and Alcalá, L. 2009. High European sauropod
dinosaur diversity during Jurassic?CCretaceous transition in Riodeva
(Teruel, Spain). Palaeontology. doi: 10.1111/j.1475-4983.2009.00898.x.
ABSTRACT: Up to now, more than 40 dinosaur sites have been found in the
latest Jurassic ?C earliest Cretaceous sedimentary outcrops (Villar del
Arzobispo Formation) of Riodeva (Iberian Range, Spain). Those already
excavated, as well as other findings, provide a large and diverse number of
sauropod remains, suggesting a great diversity for this group in the Iberian
Peninsula during this time. Vertebrae and ischial remains from Riodevan site
RD-13 are assigned to Turiasaurus riodevensis (a species described in RD-10,
Barrihonda site), which is part of the Turiasauria clade. This is the first
time that a taxon is attributed to Turiasaurus genus out of its type site. A
Neosauropod caudal vertebra from the RD-11 site has been classified as
Diplodocinae indet., supporting the previous attribution on an ilion also
found in Riodeva (CPT-1074) referring to the Diplodocidae clade. New remains
from the RD-28, RD-41 and RD-43 sites, of the same age, among which there
are caudal vertebrae, are assigned to Macronaria. New sauropod footprints
from the Villar del Arzobispo Formation complete the extraordinary sauropod
record coming to light in the area. The inclusion of other sauropods from
different contemporaneous exposures in Teruel within the Turiasauria clade
adds new evidence of a great diversity of sauropods in Iberia during the
Jurassic?CCretaceous transition. Turiasauria distribution contributes to the
understanding of European and global palaeobiogeography.
Kubo, T., and Benton, M.J. 2009. Tetrapod postural shift estimated from
Permian and Triassic trackways. Palaeontology. doi:
ABSTRACT: The end-Permian mass extinction, 252 million years (myr) ago,
marks a major shift in the posture of tetrapods. Before the mass extinction,
terrestrial tetrapods were sprawlers, walking with their limbs extended to
the sides; after the event, most large tetrapods had adopted an erect
posture with their limbs tucked under the body. This shift had been
suspected from the study of skeletal fossils, but had been documented as a
long process that occupied some 15?C20 myr of the Triassic. This study reads
posture directly from fossil tracks, using a clear criterion for sprawling
vs erect posture. The track record is richer than the skeletal record,
especially for the Early and Middle Triassic intervals, the critical 20 myr
during which period the postural shift occurred. The shift to erect posture
was completed within the 6 myr of the Early Triassic and affected both
lineages of medium to large tetrapods of the time, the diapsids and
Fortier, D.C., and Schultz, C.L. 2009. A new neosuchian crocodylomorph
(Crocodyliformes, Mesoeucrocodylia) from the Early Cretaceous of north-east
Brazil. Palaeontology. doi: 10.1111/j.1475-4983.2009.00894.x.
ABSTRACT: A new neosuchian crocodylomorph, Susisuchus jaguaribensis sp.
nov., is described based on fragmentary but diagnostic material. It was
found in fluvial-braided sediments of the Lima Campos Basin, north-eastern
Brazil, 115 km from where Susisuchus anatoceps was found, in rocks of the
Crato Formation, Araripe Basin. S. jaguaribensis and S. anatoceps share a
squamosal?Cparietal contact in the posterior wall of the supratemporal
fenestra. A phylogenetic analysis places the genus Susisuchus as the sister
group to Eusuchia, confirming earlier studies. Because of its position, we
recovered the family name Susisuchidae, but with a new definition, being
node-based group including the last common ancestor of Susisuchus anatoceps
and Susisuchus jaguaribensis and all of its descendents. This new species
corroborates the idea that the origin of eusuchians was a complex
evolutionary event and that the fossil record is still very incomplete.
Bell, P.R., and Currie, P.J. 2009. A tyrannosaur jaw bitten by a
confamilial: scavenging or fatal agonism? Lethaia. doi: 10.1111/j.1502-3931.
ABSTRACT: A partial dentary of an adult tyrannosaur from the Dinosaur Park
Formation of Alberta, Canada, preserves the embedded tooth of another
tyrannosaur within the bone. The specimen's incompleteness precludes generic
identification of either the jaw or the embedded tooth, although Gorgosaurus
and/or Daspletosaurus are most likely given the stratigraphic position. The
absence of healing around the lesion indicates the bite took place either
post-mortem or within weeks prior to the death of this animal. A post-mortem
bite can be explained by confamilial or cannibalistic scavenging.
Alternatively, the bite would represent a perimortem instance of
intrafamilial aggression that may have resulted in the death of that animal.
An estimated 6053N of bite force was required to produce the bite mark. This
specimen provides the best evidence for aggressive peri- or post-mortem
confamilial interaction among tyrannosaurs and corroborates previous studies
based on inferred tooth marks.
Hwang, S.H. 2009. The utility of tooth enamel microstructure in identifying
isolated dinosaur teeth. Lethaia. doi: 10.1111/j.1502-3931.2009.00194.x.
ABSTRACT: The identification of isolated dinosaur teeth is frequently an
uncertain process because dinosaur teeth are simple in morphology compared
to those of mammals. Teeth among genera and species within major dinosaur
clades are often identical, and damage or abrasion of teeth further
complicates their identification. To aid diagnosis of isolated teeth,
systematic descriptions of dinosaur teeth have been compiled, and
quantitative morphometric identification methods have also been developed.
However, these aids work best with relatively intact teeth. Enamel
microstructure, in contrast, can be used to identify the minutest of tooth
fragments as long as the entire enamel thickness, often <100 μm, is
preserved. In addition, enamel microstructure can be used to differentiate
isolated teeth that are similar in morphology but have different enamel,
such as ankylosaur and posterior pachycephalosaurid or basal theropod and
tyrannosaurid teeth. To evaluate the efficacy of enamel microstructure as an
identification tool, nine isolated dinosaur teeth, specimens originally
identified as 'Carnosauria' indet., Theropoda indet., Nanotyrannus sp.,
Tyrannosauridae indet., Troodontidae indet., Pachycephalosauridae indet.,
Hadrosaurinae indet. and cf. Thescelosaurus sp., were sectioned and their
enamel examined using scanning electron microscopy. Upon inspection of their
enamel microstructure, three of the specimens could be identified to genus,
and the taxonomic identity of all the specimens were better understood.
While enamel microstructure may not always constrain the identity of an
indeterminate tooth to the generic or species level, it usually allows for a
more accurate identification.
Hone, D.W.E., Sullivan, C., and Bennett, S.C. 2009. Interpreting the
autopodia of tetrapods: interphalangeal lines hinge on too many assumptions.
Historical Biology. doi: 10.1080/08912960903154503.
ABSTRACT: Recently Peters proposed the concept of 'interphalangeal lines',
defined as sub-parallel lines that could supposedly be drawn across the
joints of the digits of all tetrapods. The lines were viewed as potential
axes of rotation, and it was suggested that they could be used to determine
the resting position of the digits, reconstruct missing digital elements of
fossil tetrapods, and provide information on systematic relationships.
Evidence was adduced from the skeletons of recent and fossil vertebrates and
from footprints. However, detailed analysis shows that these claims are
largely unfounded. Linear alignments of joints on neighbouring digits are
not consistently present in tetrapods, especially across locomotor cycles.
Even if present, interphalangeal (IP) lines would rarely be in an
appropriate orientation to facilitate joint movements during locomotion.
There is no reason to believe that IP lines would be homologous across
different taxa, so they cannot be used to infer systematic relationships.
Finally, the alleged support from the ichnological record is undermined by
the uncertain relationship between the joint structure of the skeleton and
the form of the print. We conclude that IP lines cannot be consistently
constructed on tetrapod extremities, and would have minimal functional
relevance or predictive power in any case.
Jerry D. Harris
Director of Paleontology
Dixie State College
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
"Education is the only thing people
shell out a lot of money for...and
then do everything possible to avoid
getting their money's worth."