Occurrence of Libycoceras ismaeli (Zittel) in the Upper Maastrichtian of Eastern Tademait, Algerian Sahara

No ammonite has ever been reported in the Tademait plateau, Algerian Sahara, above the Turonian. A well-dated Upper Maastrichtian sequence has the first yielded Libycoceras ismaeli (Zittel) in the eastern part of the area. This stratigraphical position is correlative to the occurence of this species in the Tinrhert Hamada (Algeria) and Libya to the east and to the Tanezrouft (Algeria), Niger and eastern Mali (Sphenodiscus Zone) to the south. This find provides a new paleogeographical milestone between the Tinrhert Hamada and the Tanezrouft, along which the trans-Saharan marine channel passed on to the Iullemmeden basin in the Upper Maastrichtian.