Systematics, biostratigraphy and biogeography of four Famennian spiriferid brachiopods from Morocco

Abstract

New data on systematics, biostratigraphy and biogeography are presented in this paper. They concern four Famennian spiriferid species from South-West Morocco, discovered in Hollard's collections housed in Lille and useful for biostratigraphic and palaeobiogeographic correlations. Two of them are new: Cyrtospirifer kelbaensis n. sp., close to C. pamiricus sensu Abramian (1974, pl. 20, fig. 5, non fig. 4) not Reed, 1922 and Dichospirifer zemoulensis n. sp. close to D. cardiosinusoides (ABRAMIAN, 1957). Their systematic study is completed by a justification of their generic and specific attribution with precisions on their geographic and biostratigraphic distribution in Morocco: upper part of the Lower Famennian and lower part of the Upper Famennian (ds II — ? III sensu Hollard, 1981) for C. kelbaensis, upper part of Lower Famennian to Upper Famennian (ds II to ds V sensu Hollard, 1981) for D. zemoulensis. Two other species, recognized for the first time in Morocco, Prospira struniana (GOSSELET, 1879) and Dmitria seminoi (VERNEUIL, 1850), are compared with their type material. Their geographic and biostratigraphic distribution are stated to be in Morocco and central part of North Gondwana (North Africa and Central Asia).