Barrandicellopsis, a new Ordovician archinacelloid genus (Mollusca, Gastropoda)

 

Authors: Horný RJ

Published in: Bulletin of Geosciences, volume 75, issue 2; pages: 145 - 152;

Keywords: Mollusca, Gastropoda, Archinacelloidea, Barrandicellopsis, systematics, Ordovician, Bohemia,

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Abstract

The new genus Barrandicellopsis is based on Archinacella ovata var. elevata Barrande in Perner, 1903 from the Middle Ordovician Šárka Formation (Oretanian) of Bohemia. Apical retractor muscle attachment areas are similar to those of Barrandicella Peel et Horný, 1999 and confirm that the genus belongs to the Family Archinacellidae. It distinguishes itself by a higher shell reaching more than a half of a whorl, thicker shell wall and a slightly bell-shaped profile of the shell in maturity. Barrandicellopsis may be related to the imperfectly known genus Cyrtonellopsis Yochelson, 1958 which, however, has an asymmetrical juvenile shell. A Middle Ordovician mollusc from the Letná Formation (Berounian), originally described as Orthonychia extenuata Barrande in Perner, 1903 is tentatively assigned to this genus.