The last Frasnian Atrypida [Brachiopoda] in southern Belgium
1998; Institute of Paleobiology; Volume: 43; Issue: 2 Linguagem: Inglês
ISSN
1732-2421
Autores Tópico(s)Geological Formations and Processes Exploration
Resumo... . The last representatives of the order Atrypida on the southern flank of the Dinant Synclinorium (Vaulx-Nismes area) in Belgium belong to Costatrypa, Spinatrypa, Spinatrypina (?Spinatrypina), Spinatrypina (Exatrypa), Zowatrypa, ?Waiotrypa, Desquamatia (Desquamatia) and Desquamatia (?Seratrypa). Among the thirteen described taxa, five are new: Spinatrypa tumuli sp. n., Zowatrypa circuitionis sp. n., ?Waiotrypapluvia sp. n., Desquamatia (Desquamatia) quieta sp. n. and Desquamatia (?Seratrypa) derelicta sp. n. Supposed lissatrypid 'Glassia drevemzanni' Maillieux, 1936 from the late Frasnian Matagne shales is assigned to the Rhynchonellida. On the southern flank of the Dinant Synclinorium and in the Philippeville Massif, the Atrypida become extinct in the Palmatolepis rhenana Zone, significantly below the Frasnian-Famennian (F-F) boundary. Their extinction coincides with the first appearance of the green and black shales of the late Frasnian Matagne Formation, recording a transgressive-hypoxic event. Based on conodont data, this event takes place earlier on the southern flank of the Dinant Synclinorium than in the Philippeville Massif.
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