BRAQUIOPODOS ORDOVICICOS (ARENIGIANO) DE LA FORMACION SUR EN LA REGION DEL RIO CHASCHUIL, SISTEMA DE FAMATINA, ARGENTINA

Abstract

An Early Ordovician brachiopod fauna in the Suri Formation is described from richly fossiliferous fine-grained sandstones and volcaniclastic rocks exposed along the Chaschuil river. Brachiopods are concentrated in shell beds toward the upper part of the unit. The taxa described are: Monorthis aff. menapiae (Davidson), Paralenorthis riojanus (Levy and Nullo), Incorthis sp., Famatinorthis turneri Levy and Nullo, Plectorthidae gen. et sp. indet., Skenidioides sp. and Tritoechia sp. Of the six taxa described three were previously reported from the Arenig beds of the Precordillera basin (San Juan Formation). The Suri brachiopod assemblage shows affinities with the Celtic biogeographic province, but the record of Incorthis suggests a link with Bolivian and Moroccan brachiopod assemblages.