Ben Creisler
Some recent or older unmentioned Chinese publication papers, some in English, some in Chinese, and most with free pdfs currently available (or in the future).
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https://engine.scichina.com/doi/pdf/8D666962F9574F7D91271CAC4B1FF946?ipInfo=24.143.102.150The discovery of Hamipterus tianshanensis had important scientific significance because three-dimensional preserved fossils can provide unique information about the reproduction, development, and evolution of pterosaurs. However, the pterosaur fossils exhibited violent weathering, including noticeable cracking and spalling, since the preservation environment changed dramatically after excavation, which severely influenced the preservation of these fossils and the scientific research conducted on them. To determine the weathering mechanism of these fossil bones, the samples were analyzed using X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectrometry (SEM-EDS). The results indicate that calcite is the main mineral in the hollow bones, but it is mixed with a small amount of other minerals, such as quartz, feldspar, and other debris particles. Moreover, the main component of the pterosaur bones is hydroxyapatite, and carbonate has substituted for some of the phosphate (B-type carbonated apatite) in the fossil bones. A small amount of calcite and manganese oxides has precipitated in the vascular canals. The phosphate crystallinity index (PCI) is 4.17. These results indicate that the fossils have undergone severe diagenesis. Apart from these alterations, the fossil bones have high contents of anions and cations such as Clâ, NO3â, SO42â, Na+, and Ca2+, and the total content of soluble salts is 35584.41 Âg gâ1. Based on these results, it is inferred that the weathering mechanism of the fossil bones is as follows. First, the fragile hollow bones cracked easily because of the enormous thermal stress caused by the dramatic temperature changes in the Gobi Desert and the differences in the thermal expansion coefficients (TEC) of the surrounding rocks, the fossil bones, and the different fillers. Second, a large amount of stress is generated by salt crystallization when the temperature and humidity change, and the pterosaur fossils will be damaged when the crystallization pressure exceeds the tensile strength of the fossils. These results suggest that the preservation of pterosaur fossils requires suitable desalination and consolidation conditions. Moreover, they should be preserved in a constant temperature and humidity environment.
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S.V. Naugolnykh & V.N. Kuleshov (2020)
New palaeoclimatic insights on the Late Cretaceous environments of Mongolia based on the isotope data (Î13C, Î18O) of dinosaur eggshells and pedogenic carbonates from Bayn Dzak section.
Global Geology 23(4): 199-213 (English edition)
DOI:Â 10.3969/j.issn.1673-9736.2020.04.01
ISSN: 1673-9736 CN: 22-1371/P
http://sjdz.jlu.edu.cn/Jwk_sjdz_en/EN/abstract/abstract8744.shtml
Isotopic data obtained from the dinosaur eggshells and pedogenic nodules (pedonodules) are interpreted in terms of palaeoclimatology. The material studied originated from the Bayn Dzak locality, Southern Gobi Aimak, Mongolia, having Late Cretaceous (Campanian) age. Stratigraphically the Bayn Dzak locality belongs to the Djadokhta Formation. All the present data (lithology, type of paleosols, FPS-profiles, geochemistry), and the isotopic characteristics of the selected samples show unequivocally that the environments of the Bayn Dzak area in Late Cretaceous (Campanian) time were warm to summer-hot, seasonally dry. Wet seasons (most probably, which took place in the winter time) were not longer than two months with not more than 400 mm precipitation per year. The distribution of isotope data in the dinosaur eggshells show the main relation, which is the dependence of Î13C and Î18O values, i.e. specimens with heavy carbon isotope ratios are characterized by lighter oxygen isotope composition and conversely. Thus, the Î13C and Î18O values of the dinosaur eggshells display a clear positive correlation. It may be consequent both with the difference of the isotope composition of diet of the egg-lying animals modified by physicochemical isotope fractionation due to metabolism and changes in the isotope environment, and/or diagenetic alteration of the eggshell carbonate. Obtained isotopic data on the studied dinosaur eggshell fragments and the soil carbonates lend support to our assumption that diagenesis did not play significant role in changing the isotopic values. The distribution of Î13C and Î18O values in eggshells and in pedogenic carbonates shows the visible opposite dependencies.
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This paper aims at tackling the problem that it is difficult to monitor the weathering state of fossils in the protection of dinosaur bone fossils. Through obtaining fine 3D point cloud data of fossil surface by terrestrial laser scanning and on the basis of the comparison of three-dimensional data of two periods at an interval of 7 months, the change of the fossil surface caused by weathering was analyzed. Two dinosaur bone fossils from Zhucheng area of Shandong Province were collected for two periods of data collection, and the whole surface of the fossils and their fractures were analyzed. It is found that, during the monitoring period, there was no obvious change in the monitoring object as a whole, and there was spot change (deviation of 0.7 mm) in some parts, with the change in the main fracture area being less than 0.2 mm. The experimental results show that the monitoring method adopted in this paper can monitor the submillimeter scale changes of fossils and provide a reference for the weathering monitoring of similar fossils.
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LIU Rui-feng, LIU Hai-xin, HUANG Zhuo, WANG Ji-ning, YAO Ying-qiang & SONG Qing-wei (2020)
A preliminary study of the application of spectral technology to weathering monitoring of dinosaur bone fossils.
Acta Petrologica et Mineralogica 39(5): 596-604 (in Chinese)
http://www.yskw.ac.cn/yskwxzz/article/abstract/20200507
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http://www.yskw.ac.cn/yskwxzz/article/pdf/20200507The monitoring of fossil weathering has always been a core problem in the monitoring and protection of fossil producing areas. Spectral technology provides a feasible way for monitoring fossil weathering. In this paper, ASD fieldSpec 4 portable spectroradiometer was used to study dinosaur bone fossils in Zhucheng, Shandong Province, which has been an important site for dinosaur excavation since the 1960. The results show that the fossils with different colors and weathering degrees have different spectral characteristics and obvious identification marks. The changing characteristics of their spectral curves are of great reference significance for the monitoring of fossil weathering in the future.
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NOTE: There should be a free pdf link for this article as well, but it has not been posted yet at:
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Total 960 tetrapod specimens from the Lujiatun bed, Lower Cretaceous Yixian Formation have been identified by the Paleontological Experts Committee of Liaoning Province since 2001. The relative abundance o f1 522 different tetrapod individuals is calculated, this fauna and its geological age is analyzed based on fossil and chronostratigraphic data. The Lujiatun bed is rich in volcanic debris, representing the abrupt volcanic mud flow at the margin of sedimentary basin. The geological age of the bed is roughly Valanginian to Hauterivian, Early Cretaceous. The tetrapods are autochthonous and dominated by terrestrial dinosaurs. Among them, Psittacosaurus is the dominant genus with relative abundance about 90%. Troodontids and Repenomamus is rich in the small theropod dinosaurs and mammals, respectively. Owing to the existence of several specimen which Repenomamus and Psittacosaurus were preserved together, they are considered predator and prey. This fossil community can be named as Psittacosaurus-Repenomamus Fauna.
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Nanzhang-Yuanan Fauna is an Early Triassic marine reptile fauna, which is distributed between Nanzhang and Yuanan counties in Hubei province.The study of the Nanzhang-Yuanan Fauna started from 1950s and has made significant progress. This paper introduced the research progress of the Nanzhang-Yuanan Fauna in recent years from three aspects: the horizon of the fauna, features of marine reptile assemblages and palaeoecology. The progress indicates that the diversity of taxa and ecology, presented by Nanzhang-Yuanan Fauna, has highly developed, which provides an important evidence for studying the process of biological recovery after the end of Permian mass extinction.
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