475.3 - 471.3 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: Floian age, Early Ordovician epoch
• Ordovician of Britain: Moridunian age, Whitlandian age, Arenig epoch
• Ordovician of the Baltic: Valaste age, Latorp age, Langevoja age, Oeland epoch, Vaana age, Hunderum age, Billingen age, Saka age
• Ordovician of Ibero-Bohemia: Klabava age, Arenigian age
• Ordovician of Australia: Lancefieldian age, Chewtonian age, Bendigonian age
• Ordovician of China: Ningkuo age, Dawan age, Daobaowan age, Hunjiang age, Yiyangian age
• Ordovician of North America: Canadian age, Cassinian age, Jeffersonian age, Ibexian epoch

This interval is used in the definition of 309 collections

A total of 651 collections with 3113 occurrences lie within this time span