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标题：Taxonomy and taphonomy of Cenomanian (Upper Cretaceous) nautilids from Annopol, Poland
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作者：Marcin Machalski ; Markus Wilmsen
期刊名称：Acta geologica Polonica
印刷版ISSN：0001-5709
出版年度：2015
卷号：65
期号：4
页码：495-506
语种：English
出版社：Institute of Geology, University of Warsaw
摘要：A nautilid faunule of seven specimens, comprising Eutrephoceras bouchardianum (d’Orbigny, 1840), Cymatoceras deslongchampsianum (d’Orbigny, 1840), and Cymatoceras tourtiae (Schlüter, 1876) is described from a condensed middle Cenomanian interval at Annopol, Poland. C. tourtiae is recorded for the first time in Poland. The studied material consists of reworked phosphatised internal moulds of phragmocones, which may be of early or middle Cenomanian age, given the stratigraphic range of the associated ammonites. The nautilid moulds vary in inferred mode of infilling, and in intensity of abrasion, bioerosion and mineralisation. The sediment entered the phragmocones in two ways: 1) through punctures in the shell, the result of bioerosion or mechanical damage; 2) through siphonal openings by intracameral currents. In contrast to the fossil moulds from the Albian phosphorites of Annopol, which originated via direct precipitation of apatite around and/or inside fossils, the present nautilid moulds seem to have originated through secondary phosphatisation of the initially calcareous moulds. Diversity of taphonomic signatures in nautilid material from the middle Cenomanian interval at Annopol is compatible with the complex, multievent depositional scenario proposed for this level.
关键词：Nautilids;Condensed deposits;Taphonomy;Cenomanian;Cretaceous;Annopol;Pola