A Late Jurassic Boreal echinoderm Lagerstätte from Janusfjellet, central Spitsbergen, Arctic Norway
Institution: | University of Oslo |
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Department: | |
Year: | 1000 |
Keywords: | VDP::450 |
Record ID: | 1294786 |
Full text PDF: | https://www.duo.uio.no/handle/10852/12551 https://www.duo.uio.no/bitstream/10852/12551/1/Rousseau_2011_MSc_DUO.pdf |
A well preserved, low diversity assemblage of fossil echinoderms is described from the Volgian Slottsmøya Member (Agardhfjellet Formation) on central Spitsbergen. Five species are recognized: the isocrinid Chariocrinus sp. A, the pedinoid Hemipedina sp. A, the forcipulate asteroid Asteriidae sp. A, the ophiacanthid Ophiotreta sp. A and the ophiurid Ophiurinae sp. A. A depositional environment model reconciling autecologic, taphonomic and sedimentary evidence is presented. The Janusfjellet Lagerstätte was formed by a single, rapid burial event during a storm, which entombed together autochthonous asteroids and ophiuroids and allochthonous crinoids and echinoids on a dysoxic muddy seafloor. Comparable echinoderm material from the Boreal Late Jurassic—Early Cretaceous is scarce, outdated and usually poorly described and illustrated. The scarcity of reported occurrences probably results from a collector bias for rare complete specimens and does not reflect the true echinoderm composition of Mesozoic high-latitude communities.