Geologic Time Scale: The Paleozoic Era
| Period | Epoch | Age | Dates (m.y.) |
| Permian | Lopingian | Chianghsingian | 253.8-251.0 |
| Wuchiapingian | 260.4-253.8 | ||
| Guadalupian | Capitanian | 265.8-260.4 | |
| Wordian | 268.0-265.8 | ||
| Roadian | 270.6-268.0 | ||
| Cisuralian | Kungurian | 275.6-270.6 | |
| Artinskian | 284.4-275.6 | ||
| Sakmarian | 294.6-284.4 | ||
| Asselian | 299.0-294.6 | ||
| Pennsylvanian (Carboniferous) | Late Pennsylvanian | Gzhelian | 303.9-299.0 |
| Kasimovian | 306.5-303.9 | ||
| Middle Pennsylvanian | Moscovian | 311.7-306.5 | |
| Early Pennsylvanian | Bashkirian | 318.1-311.7 | |
| Mississippian (Carboniferous) | Late Mississippian | Serpukhovian | 326.4-318.1 |
| Middle Mississippian | Visean | 345.3-326.4 | |
| Early Mississippian | Tourniaisian | 359.2-345.3 | |
| Devonian | Late Devonian | Famennian | 374.5-359.2 |
| Frasnian | 385.3-374.5 | ||
| Middle Devonian | Givetian | 391.8-385.3 | |
| Eifelian | 397.5-391.8 | ||
| Early Devonian | Emsian | 407.0-397.5 | |
| Pragian | 411.2-407.0 | ||
| Lochkovian | 416.0-411.2 | ||
| Silurian | Pridoli | 418.7-416.0 | |
| Ludlow | Ludfordian | 421.3-418.7 | |
| Gorstian | 422.9-421.3 | ||
| Wenlock | Homerian | 426.2-422.9 | |
| Sheinwoodian | 428.2-426.2 | ||
| Llandovery | Telychian | 436.0-428.2 | |
| Aeronian | 439.0-436.0 | ||
| Rhuddanian | 443.7-439.0 | ||
| Ordovician | Late Ordovician | Hirnantian | 445.6-443.7 |
| unnamed | 455.8-445.6 | ||
| unnamed | 460.9-455.8 | ||
| Middle Ordovician | Darriwillian | 468.1-460.9 | |
| unnamed | 471.8-468.1 | ||
| Early Ordovician | unnamed | 478.6-471.8 | |
| Tremadocian | 488.3-478.6 | ||
| Cambrian | Late Cambrian | unnamed | ???-488.3 |
| Paibian | 501.0-??? | ||
| Middle Cambrian | 513-501 | ||
| Early Cambrian | 542-513 | ||
| Period | Epoch | Age | Dates (m.y.) |
Back to the top-level geologic time scale
This geologic time scale represents the working edge of historical geology, showing the latest names and dates of the smallest divisions of geologic time that are universally recognized. The Paleozoic Era is the first part of the Phanerozoic Eon. For anyone but specialists, the rounded-off dates in the Phanerozoic table are sufficient. Each of these dates also has a specified uncertainty, which you can look up at the source. For example, the Silurian and Devonian age boundaries have nearly 3 million years uncertainty, but the rest of the chronology is more securely known.
The dates and colors shown on this geologic time scale were specified by the International Commission on Stratigraphy in 2004.
