Ammonite biostratigraphy of the Middle and Upper Oxfordian in East Taimyr, East Siberia

Abstract

The new ammonite findings in East Taimyr, at the Chernokhrebetnaya river, display a full succession of Cardioceras and Amoeboceras species in the Middle and Upper Oxfordian. This succession is very close to those of Scotland and East Greenland, what permits a recognition of the standard Boreal zones. The Densiplicatum Zone, and the Tenuiserratum Zone are distinguished in the Middle Oxfordian, whereas the Glosense Zone (with Ilovaiskii Subzone, and Glosense Subzone), the Serratum Zone, the Regulare Zone, and beds with Amoeboceras ex gr. rosenkrantzi (possibly corresponding to the Rosenkrantzi Zone) are stated in the Upper Oxfordian.