Alexandrian age - Niagaran age
| International Chronostratigraphic Timescale | Silurian of North America | |||||
|---|---|---|---|---|---|---|
| Silurian | Pridoli | Cayugan | 419.2 | |||
| Niagaran | 422.5 * | |||||
| Ludlow | Ludfordian | 423 | ||||
| Gorstian | 425.6 | |||||
| Wenlock | Homerian | Lockportian | 427.4 | |||
| Sheinwoodian | 430.5 | |||||
| Llandovery | Telychian | Ontarian | 433.4 | |||
| Aeronian | 438.5 | |||||
| Alexandrian | 438.7 * | |||||
| Medinan | Clinton | 440.1 * | ||||
| 440.7 * | ||||||
| Rhuddanian | 440.8 | |||||
| 443.8 | ||||||