Preliminary report on new echinoderm Lagerstatten from the Upper Ordovician of the eastern Anti-Atlas, Morocco. - Archive ouverte HAL Access content directly
Conference Papers Year : 2010

Preliminary report on new echinoderm Lagerstatten from the Upper Ordovician of the eastern Anti-Atlas, Morocco.

Abstract

Four distinct echinoderm Lagerstatten have recently been discovered in the Upper Ordovician of the eastern Anti-Atlas, Morocco. They have yielded hundreds of exquisitely preserved specimens. Their taphonomy and associated lithology both suggest rapid, in situ burial. Here we discuss the diverse range of assemblages represented and their significance to the diversity of echinoderms in the Lower Palaeozoic. The oldest assemblage (Izegguirene Formation, lowermost Caradoc) is dominated by eocrinoids, large ophiuroids, and mitrate stylophorans associated with rare crinoids. It shows strong similarities with slightly older faunas described from the underlying Ouine-Inirne Formation (Llandeilian) in the Central Anti-Atlas. The second assemblage (lower part of the Lower Ktaoua Formation, lower-middle Caradoc) is composed of eocrinoids (Cardiocystites) and small ophiuroids (encrinasterid indet.). The third assemblage was collected in the upper part of the Lower Ktaoua Formation (lowermost Ashgill). This 'starfish' bed is dominated by ophiuroids and large solutes, associated with common diploporites and rhombiferans, and rare crinoids and mitrates. Finally, the youngest assemblage (lower part of Upper Tiouririne Formation, lower Ashgill) has yielded abundant remains of edrioasteroids and rhombiferans.

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Paleontology
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Dates and versions

hal-00522796 , version 1 (01-10-2010)

Identifiers

  • HAL Id : hal-00522796 , version 1

Cite

Aaron W. Hunter, Bertrand Lefebvre, Elise Nardin, P. van Roy, S. Zamora, et al.. Preliminary report on new echinoderm Lagerstatten from the Upper Ordovician of the eastern Anti-Atlas, Morocco.. 12th International Echinoderm Conference, Aug 2006, Durham? University of New Hampshire, United States. pp.23-30. ⟨hal-00522796⟩
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