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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 studies.

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: 10.1002/jmor.10555.

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
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


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