Échinides irréguliers de l'Albien supérieur de la Formation d'El Mizab (Bassin de Talerhza, Rides sud-rifaines, nord Maroc)

The El Mizab Formation of the Talerhza Basin (South-Riffian Rides) in the Moulay Idriss Zerhoun area, provided sixteen irregular echinoid specimens from stratigraphic levels dated by ammonites of Upper Albian (Dipoloceras cristatum-Mortoniceras (M.) inflatum zones). It consists of Coenholectypus neocomiensis (Gras, 1848), Coenholectypus sp. and Macraster aff. vatonnei (Coquand, 1862). The latter species, more abundant (14 specimens), is represented by three varieties. These echinoid species, studied and illustrated, are reported for the first time for the late Albian of the South Riffian Ridges and of Morocco. On the paleo-environmental pattern, echinofauna, associated macrofauna and lithofacies evoke for the studied stratigraphic sequence a shallow, calm and oxygenated proximal platform rich in organic material and subject to the pelagic influence.