Berriasella (Berriasella) callisto

Age: Cretaceous-Berriasian. 

Location: Gard, France.

Diameter: 6 cm.

Berriasella has a highly developed process. The ammonites have separate sexes and in some cases they display a marked sexual dimorphism, in which micro- and macroconchas are represented that respectively had to correspond to males and females. Adult microconchas develop lateral processes; instead, adult macroconchas maintain a shell with simple peristoma.