Eon Era Period Epoch Time Span (Ma) Duration (My) Phanerozoic Cenozoic Quaternary Holocene        -   0.01  0.01 Pleistocene    0.01-   1.6  1.59 Tertiary Pliocene    1.6 -   5.3  3.7 Miocene    5.3 -  23.7 18.4 Oligocene   23.7 -  36.6 12.9 Eocene   36.6 -  57.8 21.2 Paleocene   57.8 -  65  7.2 Mesozoic Cretaceous   65   - 140 75 Jurassic  140   - 205 65 Triassic  205   - 250 45 Paleozoic Permian  250   - 290 40 Carboniferous  290   - 355 65 Devonian  355   - 410 55 Silurian  410   - 438 28 Ordovician  438   - 510 72 Cambrian  510   - 540 30