451.1 - 443.8 Ma

The definition of this interval in the timescale Ordovician of North America is taken from the following source:

• F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view

The bottom age has been interpolated based on the differences between the ages for international timescale boundaries quoted in the source and the currently accepted ages for those boundaries.

There are intervals in 7 timescales which overlap this one. show

• International Chronostratigraphic Timescale: Katian age, Hirnantian age, Late Ordovician epoch
• Ordovician of Britain: Onnian age, Cautleyan age, Rawtheyan age, Streffordian age, Ashgill epoch, Pusgillian age, Caradoc epoch
• Ordovician of the Baltic: Harju epoch, Vormsi age, Pirgu age, Rakvere age, Porkuni age, Viru epoch, Johvi age, Nabala age
• Ordovician of Ibero-Bohemia: Bohdalec age, Kosovian age, Kralodvorian age, Berounian age
• Ordovician of Australia: Bolindian age, Eastonian age
• Ordovician of China: Neichianshanian age, Hanjiang age, Wufeng age, Xiaoxita age, Chientangkiangian age, Shikou age
• Ordovician of North America: Shermanian age, Franklinian age, Richmondian age, Edenian age, Kirkfieldian age, Rocklandian age, Trentonian age, Maysvillian age, Ashbyan age, Blackriveran age, Wildernessian age, Gamachian age

This interval is used in the definition of 8 collections

A total of 5488 collections with 36483 occurrences lie within this time span