First record of the Mediterranean zonal index Mesosimoceras cavouri (Gemmellaro, 1872) in the Upper Jurassic (Pseudomutabilis Zone, semicostatum γ horizon) of SW Germany and its stratigraphical significance

The ammonite species Mesosimoceras cavouri (Gemmellaro), the index of the Mediterranean Cavouri Zone, is recorded for the first time from the Submediterranean Upper Jurassic of SW Germany. It occurs in the Untere-Felsenkalke Formation, within a rich ammonite association of the late Pseudomutabilis Zone characterized by fine-ribbed variants of Aulacostephanus pseudomutabilis (de Loriol) and a still undescribed flexuous-ribbed variant of Aulacostephanus eudoxus (d’Orbigny). This ammonite association represents the here newly introduced Lingulaticeras semicostatum γ horizon. The record of Mesosimoceras cavouri (Gemmellaro) confirms at least a partial correlation of the Mediterranean Cavouri Zone with the Submediterranen Pseudomutabilis Zone and the Subboreal Eudoxus Zone.