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New Papers of the Titans

...heavy on sauropodomorph papers.  (Get it?  "Heavy"...on
sauropodomorphs...eh, never mind...)

Siegwarth, J.D., Smith, C.N., and Redman, P.D. 2010. An alternative sauropod
physiology and cardiovascular system that eliminates high blood pressures.
Lethaia. doi: 10.1111/j.1502-3931.2010.00221.x.

ABSTRACT: The long neck of an adult sauropod has been found structurally
unsuitable for high browsing while standing on all four feet. Some juveniles
might have used a tripodal stance, but an analysis of the motion of the
centre of mass shows a large adult sauropod could not. We propose here that
sauropods could have browsed high by sitting, squatting or even kneeling on
their hind legs to elevate their heads without a sharp bend at the base of
the neck. A large sauropod needs a way to deal with very high blood pressure
when high browsing. Arterial pumping is suggested here as a means of
avoiding the need for high blood pressure.

Mannion, P.D., and Upchurch, P. 2010. A quantitative analysis of
environmental associations in sauropod dinosaurs. Paleobiology
36(2):253-282. doi: 10.1666/08085.1.

ABSTRACT: Both the body fossils and trackways of sauropod dinosaurs indicate
that they inhabited a range of inland and coastal environments during their
160-Myr evolutionary history. Quantitative paleoecological analyses of a
large data set of sauropod occurrences reveal a statistically significant
positive association between non-titanosaurs and coastal environments, and
between titanosaurs and inland environments. Similarly, ?narrow-gauge?
trackways are positively associated with coastal environments and
?wide-gauge? trackways are associated with inland environments. The
statistical support for these associations suggests that this is a genuine
ecological signal: non-titanosaur sauropods preferred coastal environments
such as carbonate platforms, whereas titanosaurs preferred inland
environments such as fluvio-lacustrine systems. These results remain robust
when the data set is time sliced and jackknifed in various ways. When the
analyses are repeated using the more inclusive groupings of titanosauriforms
and Macronaria, the signal is weakened or lost. These results reinforce the
hypothesis that ?wide-gauge? trackways were produced by titanosaurs. It is
commonly assumed that the trackway and body fossil records will give
different results, with the former providing a more reliable guide to the
habitats occupied by extinct organisms because footprints are produced
during life, whereas carcasses can be transported to different environments
prior to burial. However, this view is challenged by our observation that
separate body fossil and trackway data sets independently support the same
conclusions regarding environmental preferences in sauropod dinosaurs.
Similarly, analyzing localities and individuals independently results in the
same environmental associations. We demonstrate that conclusions about
environmental patterns among fossil taxa can be highly sensitive to an
investigator's choices regarding analytical protocols. In particular,
decisions regarding the taxonomic groupings used for comparison, the time
range represented by the data set, and the criteria used to identify the
number of localities can all have a marked effect on conclusions regarding
the existence and nature of putative environmental associations. We
recommend that large data sets be explored for such associations at a
variety of different taxonomic and temporal scales.

Mannion, P.D., and Upchurch, P. 2010. Completeness metrics and the quality
of the sauropodomorph fossil record through geological and historical time.
Paleobiology 36(2):283-302. doi: 10.1666/09008.1.

ABSTRACT: Despite increasing concerns about the effect of sampling biases on
our reading of the fossil record, few studies have considered the
completeness of the fossil remains themselves, and those that have tend to
apply non-quantitative measures of preservation quality. Here we outline two
new types of metric for quantifying the completeness of the fossil remains
of taxa through time, using sauropodomorph dinosaurs as a case study. The
?Skeletal Completeness Metric? divides the skeleton up into percentages
based on the amount of bone for each region, whereas the ?Character
Completeness Metric? is based on the number of characters that can be scored
for each skeletal element in phylogenetic analyses. For both metrics we
calculated the completeness of the most complete individual and of the type
specimen. We also calculated how well the taxon as a whole is known from its
remains. We then plotted these results against both geological and
historical time, and compared curves of the former with fluctuations in
sauropodomorph diversity, sea level, and sedimentary rock outcrop area.
Completeness through the Mesozoic shows a number of peaks and troughs; the
Early Jurassic (Hettangian?Sinemurian) is the interval with highest
completeness, whereas the mid-to-Late Cretaceous has completeness levels
that are consistently lower than the rest of the Mesozoic. Completeness
shows no relationship to rock outcrop area, but it is negatively correlated
with sea level during the Jurassic?Early Cretaceous and correlated with
diversity in the Cretaceous. Completeness of sauropodomorph type specimens
has improved from 1830 to the present, supporting the conclusions of other
recent studies. However, when this time interval is partitioned, we find no
trend for an increase in completeness from the 1990s onward. Moreover, the
2000s represent one of the poorest decades in terms of average type specimen
completeness. These results highlight the need for quantitative methods when
assessing fossil record quality through geological time or when drawing
conclusions about historical trends in the completeness of taxa. The new
metrics may also prove useful as sampling proxies in diversity studies.

Sweetman, S.C., and Insole, A.N. 2010. The plant debris beds of the Early
Cretaceous (Barremian) Wessex Formation of the Isle of Wight, southern
England: their genesis and palaeontological significance Palaeogeography,
Palaeoclimatology, Palaeoecology. doi: 10.1016/j.palaeo.2010.03.055.

ABSTRACT: The Early Cretaceous (Barremian) Wessex Formation of the Isle of
Wight primarily represents high sinuosity fluvial, but also lacustrine and
terrestrial deposition on a low relief floodplain occupying half grabens,
with active normal faults immediately to the north. Plant debris beds form a
very small proportion of the succession but are the main source of
vertebrate fossils, including dinosaurs. These conspicuous, but thin, grey
units are distributed randomly throughout the Wessex Formation and are of
limited lateral extent. The lower part of most plant debris beds comprises a
poorly sorted, matrix-supported conglomerate. The upper part of most
consists of structureless mudstone, which usually grades up into colour
mottled but predominantly red and purple floodplain mudstones. The plant
debris beds contain an unusual mixture of freshwater molluscs, diverse
aquatic and terrestrial vertebrates, and mainly terrestrial plants with a
variable quality of preservation. We conclude that each plant debris bed
represents a locally generated sheetflood, which was then transformed on the
floodplain into a debris flow by the acquisition of surface material. The
debris flows surged into, and were deposited in depressions on the alluvial
plain, including abandoned chute and cut-off channels, oxbows and ponds.
These units are therefore intrabasinal and interfluvial, and the fossils
that they contain are locally derived. Similar deposits of palaeontological
significance have not been reported elsewhere in the literature. In view of
this, their origin and sedimentology, their palaeontological significance,
and the taphonomy of the flora and fauna they contain are discussed.

Suarez, C.A., Macpherson, G.L., González, L.A., and Grandstaff, D.E. 2010.
Heterogenous rare earth element (REE) patterns and concentrations in a
fossil bone: implications for the use of REE in vertebrate taphonomy and
fossilization history. Geochimica et Cosmochimica Acta. doi:

ABSTRACT: A bone fragment (CGDQ-3) of Falcarius utahensis, a therizinosaur
from the Early Cretaceous Cedar Mountain Formation, Utah, contained within a
carbonate nodule, was analyzed by laser ablation inductively coupled plasma
mass spectrometry (LA-ICP-MS) in order to investigate REE variability within
a thin-walled phalanx. Previous studies have found depth-related REE pattern
variations; however, in CGDQ-3 variation occurs along the circumference of
the bone. NASC-normalized REE patterns and concentrations vary between two
apparent end members. A light-REE enriched (LREE) pattern, similar to
solution ICP-MS analysis of this bone, characterizes approximately
two-thirds of the bone fragment. Total REE concentrations are high and do
not vary significantly from the periosteal surface to the medullar surface.
Conversely, the remaining one-third of the bone has REE patterns that are
MREE-depleted and low in total REE concentrations. REE concentrations in
this part of the bone do not vary significantly from the periosteal to the
medullar surface. A positive Ce anomaly is found throughout the entire bone,
and is greatest within the LREE-enriched portion of the bone. This, in
combination with the LREE-enrichment, suggests that the bone fossilized
under reducing conditions. The distance between the LREE-enriched and
MREE-depleted regions is less than 1 mm. Isotopic and petrographic analyses
of the bone and surrounding carbonate matrix suggest the REE patterns in the
bone were the result of partial fossilization/incomplete filling of
micro-pore spaces around bone crystallites in an environment with changing
redox conditions. The lower, MREE-depleted part of the bone fossilized
contemporaneously with a pendant cement that formed on the underside of the
bone in the vadose zone. Formation of the pendant cement restricted water
flow through the bone, isolating the lower portion, which incorporated a
MREE-depleted pattern. The upper part of the bone (LREE-enriched side)
fossilized under more reducing conditions than the lower part. This resulted
in reductive dissolution of minerals (such as hydrous ferric oxides and
manganese-oxides) which were LREE-enriched with positive Ce anomalies. These
REE were then incorporated into the upper part of the bone. This likely
occurred after the bone entered the saturated zone (below the water table).
The thinness of the bone and presence of a pendant cement helped facilitate
partial fossilization of the bone, preserving the REE signature of an
earlier fluid. As demonstrated by this case study, differences in REE
patterns within a fossil may record changes in geochemical conditions during
fossilization, particularly, when bones are encased in a material that
reduces fluid permeability, such as micritic vadose calcite. Analysis of
such bones may offer the opportunity to decipher complex fluid histories
that occur during fossilization. LA-ICP-MS should be utilized to confirm
solution ICP-MS analysis if it yields high REE variability, prior to an
interpretation of reworking or time-averaging.

Ishigaki, S. 2010. Theropod trampled bedding plane with laboring trackways
from the Upper Cretaceous Abdrant Nuru fossil site, Mongolia. Hayashibara
Museum of Natural Sciences Research Bulletin 3:133-141.

ABSTRACT: The Hayashibara Museum of Natural Sciences-Mongolian
Paleontological Center Joint Paleontological Expedition team has excavated a
bedding plane trampled by theropod dinosaurs from Abdrant Nuru fossil site,
Gobi desert, Mongolia. 14 trackways consisting of 84 footprints have been
discovered on a single exposure of the bedding plane. The depth of the
trackways varies from extremely deep to shallow, proving sequential
imprinting during the drying and hardening process of the substrate. Deep
footprints and elongated footprints are not useful for ichnotaxonomy, but
they are useful for studying the laborious locomotion of the trackmakers on
soft substrate.

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

"I have noticed even people who
claim everything is predestined, and
that we can do nothing to change it,
look before they cross the road."

                   -- Stephen Hawking

"Prediction is very difficult,
especially of the future."

                   -- Niels Bohr