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The New Papers Knight



Sorry I've been lapse on reporting of late (like it's never happened
before...), but here's a few newbies:


He, T., Wang, X.-L., and Zhou, Z.-H. 2008. A new genus and species of
caudipterid dinosaur from the Lower Cretaceous Jiufotang Formation of
western Liaoning, China. Vertebrata PalAsiatica 46(3):178-189. 

ABSTRACT: Anew oviraptorosaur, Similicaudipteryx yixianensis gen. el sp.
nov. is described from the Jiufotang Formation (120 Ma) of the Jeho1 Group
in western Liaoning. China. which is referred to the Caudipteridae based on
a dagger-like pygostyle and the shape of the ilium that are most similar to
those of Caudipteryx. It differs from other oviraptorosaurids in that the
ratio of pubis to ilium length is 1.46 and the presence of two large and
deep hypapophyses on dorsal vertebrae. The known caudipterids have
previously been found only from the Jianshangou Member of the Yixian
Formation (125 Ma) of the Sihetun area in Liaoning Province. S. yixianensis
represents the first caudipterid dinosaur from the Jiufotang Formation. The
new discovery provides more information for the discussion of the evolution
of oviraptorids during the Early Cretaceous and adds to the dinosaur
assemblage of the Jehol Biota.



Martinelli, A.G., and Pais, D.F. 2008. A new baurusuchid crocodyliform
(Archosauria) from the Late Cretaceous of Patagonia (Argentina). Comptes
Rendus Palevol 7(6):371-381. doi: 10.1016/j.crpv.2008.05.002. 

ABSTRACT: A new baurusuchid, Wargosuchus australis gen. et sp. nov., coming
from the Bajo de La Carpa Formation, Neuquén Province (Argentina), is
described. This new taxon is based on a fragment of snout and a portion of
the cranial roof. Wargosuchus differs from other crocodyliforms by
possessing a deep median groove on the frontals, a contact between nasals
and frontals extremely reduced, a large depression for the olfactory bulbs,
three large foramina surrounding the large, smooth perinarial depression,
and a hypertrophied, conical last premaxillary tooth followed by a large
paracanine fossa. The finding of Wargosuchus in Patagonia (Argentina), a
taxon with a strong resemblance to Brazilian baurusuchids, reinforces the
hypothesis of a similar biota between both regions by the Late Cretaceous.
Wargosuchus and Cynodontosuchus represent the only Argentinian
mesoeucrocodylians to be included within Baurusuchidae. This finding extends
the number of crocodyliforms from the Bajo de la Carpa Formation, which, in
turn, corresponds to the most taxonomically diverse one in Argentina.




Bell, P.R., and Snively, E. 2008. Polar dinosaurs on parade: a review of
dinosaur migration. Alcheringa 32(3):271-284. doi:
10.1080/03115510802096101. 

ABSTRACT: Cretaceous polar dinosaur faunas were taxonomically diverse, which
suggests varied strategies for coping with the climatic stress of high
latitudes. Some polar dinosaurs, particularly larger taxa such as the
duckbill Edmontosaurus Lambe, 1917, were biomechanically and energetically
capable of migrating over long distances, up to 2600 km. However, current
evidence strongly suggests many polar dinosaurs (including sauropods, large
and small theropods, and ankylosaurs of New Zealand) overwintered in
preference to migration. Certain groups also appear more predisposed to
overwintering based on their physical inability (related to biomechanics,
natural history, or absolute size) to migrate, such as ankylosaurs and many
small taxa, including hypsilophodontids and troodontids. Low-nutrient
subsistence is found to be the best overwintering method overall, although
the likelihood that other taxa employed alternative means remains plausible.
Despite wide distribution of some genera, species-level identification is
required to assess the applicability of such distributions to migration
distances. Presently, such resolution is not available or contradicts the
migration hypothesis.




Fricke, H.C., Rogers, R.R., Backlund, R., Dwyer, C.N., and Echt, S. 2008.
Preservation of primary stable isotope signals in dinosaur remains, and
environmental gradients of the Late Cretaceous of Montana and Alberta.
Palaeogeography, Palaeoclimatology, Palaeoecology 266(1-2):13-27. doi:
10.1016/j.palaeo.2008.03.030. 

ABSTRACT: Although the use of stable isotope data from vertebrate remains is
becoming common for the Cenozoic, their application to Mesozoic environments
has been rare, in part due to the perception that diagenesis has obfuscated
all potential primary signal. In this paper, we illustrate how stable
isotope data collected from dinosaur and other vertebrate remains can in
fact be used to reconstruct paleoenvironmental conditions during the
Mesozoic.
     Carbon and oxygen isotope ratios were measured from tooth enamel of
hadrosaur dinosaurs and from scales of freshwater fish that were collected
from sites in the Two Medicine, Judith River, and Dinosaur Park Formations
of Montana and Alberta. These formations represent a coastal to upland
gradient along the western margin of the Late Cretaceous inland seaway.
Isotopic comparisons among skeletal components and among taxa are used as
evidence that primary paleoenvironmental information, as recorded by isotope
data, is preserved in tooth enamel and freshwater fish scales. A comparison
of carbon isotope ratios between hadrosaur tooth enamel and sedimentary
organic matter indicates that these animals had a larger isotopic offset
compared to bulk diet than modern mammals, and that all hadrosaurian isotope
data are consistent with the existence of C3-only ecosystems.
     Higher and more variable carbon and oxygen isotope ratios from animals
occupying the coastal Judith River region are interpreted to reflect a range
of freshwater to brackish water conditions and plants that were undergoing
water stress. Lower and less variable carbon and oxygen isotope ratios from
the upland Two Medicine and intermediate Dinosaur Park areas are interpreted
to reflect a gradual rainout of moisture from air masses moving inland and
more uniform environmental conditions. Overall, these results indicate that
stable isotopes from dinosaur and other vertebrate remains have the
potential to expand our understanding of terrestrial environments and
ecosystems during the Mesozoic.





Turner-Walker, G., and Jans, M. 2008. Reconstructing taphonomic histories
using histological analysis. Palaeogeography, Palaeoclimatology,
Palaeoecology 266(3-4):227-235. doi: 10.1016/j.palaeo.2008.03.024. 

ABSTRACT: Recent years have seen rapid advances in the understanding of
diagenetic changes to bone tissues and how these influence the chemistry,
microstructure and histological appearance of ancient bone. It is now
possible to recognise many characteristic features of diagenetically
modified bone and this has led to the potential use of these parameters in
estimating the potential survival of biogenic signals such as DNA, lipids,
proteins and stable isotopes. These characteristic features also hold the
potential for preserving a record of different post-mortem environments in
individual bones or assemblages of bones from the same site. In sites where
the burial conditions have changed over archaeological or geological
timescales, histological analyses can shed light on these different burial
environments and permit the reconstruction of taphonomic histories of some
bones. Examination of polished sections of bone using BSE-SEM has been used
to identify characteristic features attributed to aerobic soil bacteria,
cyanobacteria, and sulphate reducing bacteria. The approach shows promise
for providing supplementary evidence when phasing complex sites, such as
graveyards, which developed over several hundred years.




Pevzner, P.A., Kim, S., and Ng, J. 2008. Comment on "Protein sequences from
mastodon and Tyrannosaurus rex revealed by mass spectroscopy". Science
321:1040. doi: 10.1126/science.1155006. 

ABSTRACT: Asara et al. (Reports, 13 April 2007, p. 280) reported sequencing
of Tyrannosaurus rex proteins and used them to establish the evolutionary
relationships between birds and dinosaurs. We argue that the reported T. rex
peptides may represent statistical artifacts and call for complete data
release to enable experimental and computational verification of their
findings.





Asara, J.M., Schweitzer, M.H., Cantley, L.C., and Cottrell, J.S. 2008.
Response to comment on "Protein sequences from mastodon and Tyrannosaurus
rex revealed by mass spectroscopy". Science 321:1040. doi:
10.1126/science.1157829. 

ABSTRACT: Endogenous peptide sequences extracted from a 68-million-year-old
Tyrannosaurus rex fossil bone and obtained by mass spectrometry have been
shown to be statistically significant based on protein database searches
using two different search engines and similarity comparisons to authentic
tandem mass spectrometry spectra. Specifically, we have validated the
sequence GVVGLP(OH)GQR.





Rybczynski, N., Tirabasso, A., Cuthbertson, R., and Holliday, C. 2008. A
three-dimensional animation model of Edmontosaurus (Hadrosauridae) for
testing chewing hypotheses. Palaeontologica Electronica 11(2):9A (1-14). 

ABSTRACT: Here we describe a 3-D animated model of the craniodental system
of a hadrosaur, developed for testing hypotheses of feeding kinematics. The
model was created from scanned cranial elements of an Edmontosaurus regalis
paratype (CMN 2289). Movements within the model were created in animation
software using inverse kinematics and a wiring system composed of cranial
elements. The model was used to reproduce the pleurokinetic hypothesis of
hadrosaur chewing. The pleurokinetic hypothesis, formally developed in the
1980s, proposed that hadrosaurs employed transverse chewing movements via
cranial kinesis. Specifically during the powerstroke the maxillae were
abducted. This is the first model to allow investigation into secondary
intracranial movements that must have occurred in order for the skull to
accommodate the primary, pleurokinetic movements. This study found secondary
movements to be extensive among the joints of the palate and face. Further
refinement and development of the model, including the integration of
soft-tissue structures, will allow for a more in-depth examination of the
pleurokinetic hypothesis and comparison with alternative feeding hypotheses.







~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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/

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