T301 Echinoderm Paleobiology: Diversity, Form, and Phylogeny (Posters)
Wednesday, 4 November 2015
9:00 AM - 6:30 PM
Exhibit Hall
MESOZOIC NEPTUNIAN DIKES FROM SOUTHERN POLAND-INSIGHTS INTO THE FOSSIL CRYPTIC ECHINODERM FAUNA
Paper number: T301-3
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM
Authors
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Katarzyna Lesko Presenting AuthorFaculty of Earth Sciences, University of Silesia in Katowice, Sosnowiec
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Tomasz BrachaniecFaculty of Earth Sciences, University of Silesia in Katowice, Sosnowiec
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Krzysztof SzopaFaculty of Earth Sciences, University of Silesia in Katowice, Sosnowiec
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Krzysztof R. BromFaculty of Earth Sciences, University of Silesia in Katowice, Sosnowiec
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Mariusz A. SalamonFaculty of Earth Sciences, University of Silesia in Katowice, Sosnowiec
Abstract
Neptunian dikes are formed by sediment filling fissures exposed to the seafloor. They may provide unique insights into fauna inhabiting submarine crytpic cave paleoenvironments. In the epicratonic Poland, neptunian dikes are especially well known in the Upper Jurassic (mainly Oxfordian) strata. However, the age, origin and faunal composition of these dikes are still the subject of controversies. Our new data suggest complex origin of the studied dikes. Initially, they represented fissures in the sea bottom arised from the intense synsedimentary processes in the Late Jurassic. These voids were colonized mostly by small crinoids (cyrtocrinids belonging to Eugeniacrinites). Although similar modern analogues of cryptic ecosystems comprising of cyrtocrinids are known, fossil examples have been lacking up until now. Our data thus provide the first fossil record of cryptic cyrtocrinids and suggest that migration of these echinoderms to cryptic habitats has already occurred in the Late Jurassic.