The Upper Cretaceous elasmobranch fauna from Senegal

Abstract

Three successive horizons were sampled by bulk-sampling across the Campanian–Maastrichtian marine succession at the Cap de Naze cliff, South of Popenguine, Senegal. The material collected includes several hundreds of elasmobranch micro-remains as well as surface-collected specimens that are described in the present work. Twenty-six species are recorded, including three new genera and eight new batomorph species (Ptychotrygon nazeensis sp. nov., Terangabatis thiami gen. et sp. nov., ‘Rhinobatos’ popenguinensis sp. nov., Atlantobatis acrodonta gen. et sp. nov., Sowibatos minimus gen. et sp. nov., ‘Dasyatis’ reticulata sp. nov., Coupatezia casei sp. nov., Phosphatodon cretaceus sp. nov.). These new samplings complement previous records based on surface collection of the Cape de Naze section and bring the number of elasmobranch species for this fauna to 31. Increasing elasmobranch taxonomic diversity throughout the three successive assemblages indicates a transition from restricted marine to open coastal settings. This high-diversity fauna is dominated by necto-benthic batomorphs and is similar in its structure to other Tethyan and Eastern Atlantic Maastrichtian faunas. The high number of species apparently endemic to the studied area suggests high habitat differentiation in corresponding marine Maastrichtian settings. The presence of typical Maastrichtian species in the top of Unit 1 argues against a Campanian age previously proposed for this unit, while our data support a middle–late Maastrichtian age for the ferruginous sandstone bed of Unit 3.