Middle Jurassic Gastropods from the Central High Atlas, Morocco

This systematic study considers twenty-four gastropod species recovered in the Upper Aalenian - Lower Bajocian sediments of the Central High Atlas. Twenty-one species belong to archaeogastropod groups and three species are assigned to two caenogastropod families. A new genus, Sadkia nov. gen. (family Eucyclidae), and two new species, Sadkia richensis nov. sp. and Pirper ouchenensis nov. sp., are described. This gastropod fauna is compared with the coeval faunas known from other regions in order to define better the palaeobiogeographical history of the western Tethyan gastropods during the Jurassic. The generic/subgeneric and specific palaeogeographical distributions indicate a close resemblance between the gastropod faunas of the Central High Atlas and those of the European continental seas. On the other hand, there are no evidences of relationships with the faunas of the inner area of the western Tethys.