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A. Yu. Ivantsov 《Stratigraphy and Geological Correlation》2013,21(3):252-264
Metazoan trace fossils from the Upper Vendian are preserved together with remains of corresponding organisms. The traces belong to “Vendobionta”, representing the Precambrian phylum Proarticulata and to a presumably trochophoran animal Kimberella quadrata. These organisms fed on microbial mats, which preserved fossil traces. Impressions of the mat surface structures, traces, and bodies of animals are preserved in marine terrigenous sediments on the basal surfaces of sandstone beds. Proarticulata grazing traces are represented by groups and chains of impressions left by the ventral side of a body or its central and posterior parts. Kimberella traces are represented by long ridges united into bundles, fans, and chains of fans. All these traces were largely formed mechanically, i.e., by mat scratching with cilia (Proarticulata) or teeth (Kimberella). Proarticulata representatives destroyed only a thin upper layer of the mat, while Kimberella could possibly scratch the mat through its entire thickness or even tear off pieces from it. 相似文献
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A. V. Ivantsov 《Kinematics and Physics of Celestial Bodies》2007,23(2):65-69
A numerical model of motion for asteroids was developed on the basis of the DE405 theory. The positions of main-belt asteroids are calculated accurate to 0.03 mas when the integration is taken over a 50-year interval. For the model to be computationally stable, the local truncation error of integration should be equal to 10?14 and the double precision of the Standard for Binary Floating-Point Arithmetic IEEE 754-1985 should be used. 相似文献
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Lopatin A. V. Averianov A. O. Kuzmin I. T. Boitsova E. A. Saburov P. G. Ivantsov S. V. Skutschas P. P. 《Doklady Earth Sciences》2020,494(1):667-669
Doklady Earth Sciences - The first finding of the docodontan (a lower molar of Sibirotherium sp.) from the Bol’shoi Kemchug 3 locality (Ilek Formation, Lower Cretaceous) in Krasnoyarsk... 相似文献
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A. V. Ivantsov 《Kinematics and Physics of Celestial Bodies》2007,23(3):108-115
The masses of 21 main-belt asteroids were determined by the dynamical method. The masses of 13 asteroids have relative errors of less than 50 percent. When earlier positional observations are excluded and recent, highly accurate ones are used, the error of asteroid mass determination is reduced. 相似文献
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Doklady Earth Sciences - This paper clarifies the structure of the Bol’shoi Ilek section (height up to 83 m), which is composed by the deposits of Cretaceous and Quaternary systems, in the... 相似文献
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S. V. Ivantsov L. I. Bystritskaya S. A. Krasnolutskii K. P. Lyalyuk A. O. Frolov A. S. Alekseev 《Stratigraphy and Geological Correlation》2016,24(5):486-502
On the basis of the lithological-facies analysis, it was established that deposits of the Upper Itat Subformation, comprising the Dubinino locality of the Middle Jurassic flora and insects (Sharypovo district, Krasnoyarsk krai), accumulated in alluvial and lacustrine and, to a lesser extent, floodplain environments (floodplain and alluvial fan facies). The occurrence of remains of insects, macroremains of flora, spores, and pollen allowed us to make a paleoreconstruction of an area with a strongly dissected relief: continental fresh-water reservoir (lake) with varying degree of overflow, surrounded by hills covered with gymnospermous and ginkgo forests. 相似文献
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A. Yu. Ivantsov 《Stratigraphy and Geological Correlation》2013,21(6):592-600
The morphology and stratigraphic distribution of Harlaniella podolica Sokolov, 1972 and H. ingriana Ivantsov, sp. nov. were investigated using the collection of impressions sampled recently in Upper Vendian sections of Russia (southeastern White Sea region) and Ukraine (Podoliya). These fossils, which were previously considered as representing coprolites or grazing or locomotion traces, are interpreted as internal casts and impressions of fragments of tubes of initially organic composition. Streptichnus narbonnei Jensen et Runnegar, 2005 from Vendian-Cambrian boundary strata of Namibia are also attributed to this group. It is assumed that the tubes are similar to remains of the algal genera Vendotaenia Gnilovskaya, 1971 from Vendian deposits of the East European Platform and Liulingjitaenia Chen et Xiao, 1992 from Sinian sections of China. 相似文献
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A. Yu. Ivantsov 《Doklady Earth Sciences》2017,472(2):143-146
It has been established that terrigenous units of mainly carbonate deposits of the Yudoma Group in the Uchur–Maya Region of the Siberian Platform contain an assemblage of Late Vendian Ediacaran-type macrofossils. The assemblage contains species such as Aspidella terranovica, Beltanelliformis brunsae, Nenoxites curvus, and Palaeopascichnus sp., which had widespread geographic distribution. Finds of Ediacaran fossils in fossil-rich deposits of the Yudoma Group have expanded the possibilities of using the classic biostratigraphic approach applied for subdivision and global correlation of carbonate deposits in Late Precambrian paleobasins. 相似文献
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Emel’yanov N. V. Arlot J.-E. Zhang X. L. Bradshaw J. De Cat P. Han X. L. Ivantsov A. Jindra J. Maigurova N. Manek J. Pauwels T. Pomazan A. Vingerhoets P. 《Solar System Research》2019,53(6):436-442
Solar System Research - Photometric observations of satellites during their mutual occultations and eclipses are a valuable source of astrometric data for studying the motion of natural planetary... 相似文献
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Doklady Earth Sciences - Two new localities of Mesozoic mammals have been discovered: Bol’shoi Ilek and the Berezovaya River (Russia, Krasnoyarsk Territory, Lower Cretaceous, Ilek Formation).... 相似文献
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