440.1 - 422.5 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 and bottom ages have 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 5 timescales which overlap this one. show

• International Chronostratigraphic Timescale: Wenlock epoch, Aeronian age, Ludfordian age, Homerian age, Gorstian age, Telychian age, Llandovery epoch, Ludlow epoch, Pridoli epoch, Sheinwoodian age
• Silurian of the Baltic: Jaani age, Adavere age, Kaugetuma age, Paadla age, Rootsikula age, Jaagarahu age, Raikkula age, Kuressaare age
• Silurian Ages of Europe: Whitwellian age, Gleedonian age
• Silurian of England: Woolhope age, Coalbrookdale age, Temeside Shales age, Downton Castle age, Wych age, Tickwood age, Red Downtonian age, Wenlock (England) age, Buildwas age, Bringewood age, Cowleigh Park age, Elton age
• Silurian of North America: Lockportian age, Alexandrian age, Ontarian age

This interval is used in the definition of 15 collections

A total of 6851 collections with 52973 occurrences lie within this time span