Crinoids (Crinoidea, Echinodermata) from the Middle Jurassic (Callovian) of eastern Poland: a case study from the Żebrak IG 1 borehole

Mariusz A. Salamon, Anna Feldman-Olszewska

Abstract


A taxonomic account of the Callovian crinoid fauna from the Żebrak IG 1 borehole (eastern Poland) is presented. The assemblage contains numerous isocrinid ossicles (Isocrinidae) assigned to the following taxa: Isocrinus cf. nicoleti (Desor), Isocrinus sp., Chariocrinus andreae (Desor), Balanocrinus cf. subteres (Münster in Goldfuss) and Pentacrinites sp. These isocrinids are associated with a few ossicles of cyrtocrinids (Cyrtocrinida; Cyrtocrinida indet.). The crinoid remains are poorly preserved; they all are isolated ossicles, showing broken margins and/or abraded surfaces. Such a state of preservation documents a long distance of transportation and/or re-deposition in a high-energy, shallow-water setting. The crinoid assemblage differs significantly from those of southern Poland (the Polish Jura Chain and the Mesozoic margin of the Holy Cross Mountains), in which sessile crinoids, such as cyrtocrinids (Cyrtocrinida), inhabiting mostly deeper-water carbonate facies, are predominant.


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DOI: https://doi.org/10.14241/asgp.2018.007