Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous.It is named after Valangin, a small town north of Neuchâtel in the Jura Mountains of Switzerland.The base of the Valanginian is at the first appearance of calpionellid species Calpionellites darderi in the stratigraphic column.The top of the Valanginian (the base of the Hauterivian) is at the first appearance of the ammonite genus Acanthodiscus.The Upper substage begins at the first appearance of ammonite species Saynoceras verrucosum and the major marine transgression Va3.