Discovery of the jaw apparatus of the upper Volgian Ammonite Kachpurites fulgens (Craspeditidae)

The jaw apparatus of the genus Kachpurites (Ammonoidea, Craspeditidae), consisting of a pair of aptychi and a beak-shaped upper jaw is described and figured for the first time. A new aptychus species Praestriaptychus fulgens sp. nov. is established. Aptychi of this species are elongated-triangular, weakly ribbed, with a well-developed inner organic layer and a considerably thinner, often poorly preserved external calcite layer. Specimens of the type series were found in the body chamber of ammonites Kachpurites fulgens (Trautschold), from the Upper Jurassic (Upper Volgian) Kachpurites fulgens Zone of Moscow and the Moscow Region.