New crabs (Crustacea, Decapoda) from the Upper Cretaceous (Campanian) of the Moyenne Moulouya, northeast Morocco

Abstract

The presence of the genera Costacopluma and Ophthalmoplax in Upper Cretaceous (Campanian) Moroccan strata is documented on the basis of specimens collected from the Calcaires à slumps de Taghit Formation, Moyenne Moulouya (Morocco). Two new species are described, Ophthalmoplax minimus and Costacopluma maroccana. The first record for Opthalmoplax in the west Tethyan realm is reported, and systematic affinities of this genus and its species are discussed. An absolute age of the late Campanian was obtained for this assemblage from 87Sr/86Sr analysis applied to well preserved cuticle calcitic remains of Ophthalmoplax minimus. Costacopluma maroccana represents the 14th species for this genus and the fourth Cretaceous species. Its morphology reinforces hypothesis of two main phyletic groups for this genus.