423 - 421.3 Ma

The definition of this interval in the timescale Silurian of England is taken from the following source:

• W. B. Harland, R. L. Armstrong, A. V. Cox, L. E. Craig, A. G. Smith and D. G. Smith. 1990. A Geologic Time Scale 1989. view

There are intervals in 4 timescales which overlap this one. show

• International Chronostratigraphic Timescale: Pridoli epoch
• Silurian of the Baltic: Ohesaare age, Kaugetuma age
• Silurian of England: Red Downtonian age, Temeside Shales age, Bringewood age, Downton Castle age
• Silurian of North America: Niagaran age, Cayugan age

This interval is used in the definition of 5 collections

A total of 32 collections with 160 occurrences lie within this time span