Abstract In the Alpstein massif of north-eastern Switzerland, a complete succession uppermost Hauterivian to Barremian condensed hemipelagic sediments crops out. This is known as Tierwis Formation, comprising in ascending order, Altmann and Drusberg members. The sedimentary bears number fossiliferous glauconite- or phosphate-rich beds. A large newly discovered ammonites from these key beds seve...