The In Beceten Formation, also Beceten or Ibecten is a Coniacian to Santonian geologic formation in the Iullemmeden Basin of Niger. It has yielded a diverse fauna and some angiosperms. Among others, it has yielded polypterifoms, urodeles, anurans, and turtles. Dinosaur remains are among the other fossils that have been recovered from the formation, although none have yet been referred to a specific genus. The lithology primarily consists of clays, fine limestones and sandy clays.