443.8 - 438.7 Ma

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

• F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view

The top 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 4 timescales which overlap this one. show

• International Chronostratigraphic Timescale: Rhuddanian age, Llandovery epoch, Aeronian age
• Silurian of the Baltic: Juuru age, Raikkula age, Adavere age
• Silurian of England: Wych age, Cowleigh Park age
• Silurian of North America: Niagaran age, Ontarian age, Clinton age, Medinan age

This interval is used in the definition of 67 collections

A total of 1813 collections with 10337 occurrences lie within this time span