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3:10 to New Papers
A current title! (Thanks, Angela!) And two lists in one day!
Lee, Y.-N. 2007. New theropod teeth from the Juji Island (Hasandong
Formation), Daedo-ri, Hadon County, south Gyeongsang Province. Journal of
the Geological Society of Korea 43(2):151-166.
ABSTRACT: Three new theropod teeth were discovered in the Juji Island
(Hasandong Formation), Daedo-ri, Hadong County, South Gyeongsang Province in
2002. Although they are isolated teeth, I assume that they are belonging to
the same kind of animal because they were found close each other on the same
horizon, showing the same dental features. Especially, the crown height of
one tooth is 81 mm which is the largest theropod tooth ever found in Korea.
They are most similar to Acrocanthosaurus when plotting on "theropod
standard data set". These teeth represent a new theropod dinosaur in Korea
because they have different morphology from teeth known before. Comparisons
to Early Cretaceous theropods in East Asia, they are similar to Prodeinodon
(nomen dubium) from China and Mongolia. They also indicate that there were a
variety of theropod dinosaurs lived in Korean peninsula including the large
"carnosaurid" more than 10 m in length.
Moore, J.R., Norman, D.B., and Upchurch, P. 2007. Assessing relative
abundances in fossil assemblages. Palaeogeography, Palaeoclimatology,
Palaeoecology 253(3-4):317-322. doi: 10.1016/j.palaeo.2007.06.004.
ABSTRACT: The relative abundances of taxa or skeletal elements in a fossil
assemblage can provide important information concerning the palaeoecology
and taphonomy of the assemblage. However, these relative abundances must be
estimated from samples of the assemblage, rather than measured directly. The
sampling error this produces decreases the accuracy with which relative
abundances can be estimated from the fossil record. Using the multinomial
distribution it is possible to place constraints on the accuracy of
estimation of relative abundance, provided that two out of three key
parameters (sample size, required degree of similarity and confidence level)
are known. Applying this methodology to the fossil record it can be shown
that in order to be 95% confident the taxon relative abundances of a fossil
assemblage lie within 5% of those found in a sample, 534 individuals must be
collected. This methodology enables the assessment of published relative
abundance estimates and the development of sampling protocols for future
Fürsich, F.T., Sha, J., Jiang, B., and Pan, Y. 2007. High resolution
palaeoecological and taphonomic analysis of Early Cretaceous lake biota,
western Liaoning (NE-China). Palaeogeography, Palaeoclimatology,
Palaeoecology 253(3-4):434-457. doi: 10.1016/j.palaeo.2007.06.012.
ABSTRACT: The faunal content of eighteen bedding planes within the
Jianshangou Unit of the Lower Cretaceous Yixian Formation of western
Liaoning has been analysed in detail in order to understand the
environmental and taphonomic framework of this famous lacustrine
fossillagerstätte. The bedding planes were excavated within a 3 m thick
section, which is composed of laminated mudstones, graded sandstones and
mudstones, and horizontally stratified structureless sandstones and tuffs.
All investigated bedding planes occur within the laminated mudstone facies
and contain elements of the so-called Jehol Biota, in particular the
conchostracan Eosestheria ovata, the ephemerid nymph Hexagenites trisetalis
and the crustacean Liaoningogriphus quadripartitus. These three faunal
elements occur in high abundance, originally possessed chitinous skeletons
and are preserved as compressed, faintly mineralized coats or, in the case
of Eosestheria, still possess organic material. The specimens do no
represent exuviae, but body fossils. The fossils can be grouped into three
low diversity associations, each characterized by one of the three taxa. The
plan-view orientation of the taxa is invariably random and size frequency
histograms are bimodal or polymodal. This indicates that the fauna is
autochthonous and that the histograms reflect several recruitment phases.
Apparently, the faunal elements suffered seasonal mass mortality caused by
anoxic conditions, which became established in the lake during the summer
months. Increased humidity during the winter led to mixing of the lake
waters, re-establishment of oxic conditions and to deposition of a thin film
of sediment. Such environmental conditions were episodically interrupted by
flash floods and volcanic ash falls, which may have been responsible for the
preservation of the more spectacular elements of the Jehol biota such as
birds and feathered dinosaurs.
Brewer, M.L., and Hertel, F. 2007. Wing morphology and flight behavior of
pelecaniform seabirds. Journal of Morphology 268(10):866-877. doi:
ABSTRACT: The selective pressures associated with flight are significant
factors in shaping the morphology of volant forms. Tropical seabirds are of
particular interest because of their long foraging bouts, which can last
hundreds of kilometers in search of unpredictable (spatially and temporally)
resources. Here, we contrast wing loading (WL), aspect ratio (AR), and
planform shape among five pelecaniform seabirds and correlate morphological
diversity with known differences in flight strategies. Overall, WL and AR
scaled with body mass. The Great Frigratebird had lower WL than that
predicted, whereas the Red-tailed Tropicbird had higher WL than that
predicted. The tropicbird also exhibited a lower AR than that predicted.
Visualization of planform shape was accomplished by using Thin-plate spline
relative warp analysis (TPS/RWA), and three major regions of variations were
discovered: wing base, mid-wing, and distal wing/wing tip. As expected, the
three boobies were more similar than either the tropicbird or the
frigatebird. The tropicbird had a broader distal wing and more rounded wing
tip, associated with its greater use of flapping flight. The frigatebird
showed the greatest deviation in the distal wing and wing tip associated
with the high maneuverability required for aerial pursuit and
kleptoparasitism. By using TPS/RWA, important differences were detected in
planform shape that would have otherwise gone unnoticed when using only WL
and AR. These differences correlated strongly with parameters such as
maneuverability, flapping, and soaring flight.
Therrien, F., Eberth, D.A., Braman, D.R., and Zelenitsky, D.K. 2007.
High-resolution organic carbon isotope record across the Cretaceous-Tertiary
boundary in south-central Alberta: implications for the post-impact recovery
rate of terrestrial ecosystems and use of delta13C as a boundary marker.
Canadian Journal of Earth Sciences 44(4): 529-542.
ABSTRACT: A high-resolution study identified a delta13C excursion of -1.8?
to -2.3? in terrestrial organic matter across the Cretaceous-Tertiary (K-T)
boundary at two localities in the Scollard Formation of south-central
Alberta, one of the northernmost occurrences of the K-T boundary in
terrestrial settings. delta13C values are at their lowest within 6 cm above
the K-T boundary claystone and return to pre-boundary levels within 10 cm
above the boundary claystone. Statistical analyses reveal that the K-T
isotopic shift in Alberta is related to the nature of floral changes that
occurred across the K-T boundary. A radiometrically dated bentonite resting
on the boundary-hosting Nevis coal at one of the localities permits us to
estimate that the terrestrial carbon cycle recovered ~100 000 years after
the K-T boundary event, a value that supports an existing hypothesis that
terrestrial ecosystems recovered more rapidly than marine ecosystems. The
organic carbon isotope record of the entire Scollard Formation demonstrates
that the delta13C excursion across the K-T boundary did not reach
anomalously low values by late Maastrichtian standards in Alberta.
Furthermore, the occurrence of the K-T carbon isotope shift within a
restricted stratigraphic interval (<10 cm) greatly limits the probability of
its preservation in the context of terrestrial sedimentary environments.
These observations suggest that, on their own, delta13C profiles may be
unreliable for locating the K-T boundary (and possibly other geologically
instantaneous events) and that they should be used in combination with other
approaches (e.g., palynology) to identify the K-T boundary in sections
lacking the boundary claystone and iridium anomaly.
(uh, I replaced all the actual lowercase deltas in that abstract with the
word "delta" -- I wasn't certain how it might come through otherwise...
That aside: K-Pg! K-Pg! K-Pg!!!)
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
STORIES IN SIX WORDS OR LESS:
"Machine. Unexpectedly, I'd invented
-- Alan Moore
"Easy. Just touch the match to"
-- Ursula K. Le Guin
"Batman Sues Batsignal: Demands
-- Cory Doctorow