AGES EXPLAINED

Major Era

Geologic Time

How Many Years Ago?

Cenozoic

Recent

0 - 9 Thousand Years

Pleistocene

10 Thousand - 1.5 Million Years

Pliocene

1.5 - 5 Million Years

Miocene

5 - 23 Million Years

Oligocene

23 - 33 Million Years

Eocene

33 - 56 Million Years

Paleocene

55 - 65 Million Years

Mesozoic

Cretaceous

65 - 140 Million Years

Jurassic

140 - 220 Million Years

Triassic

220 - 245 Million Years

Paleozoic

Permian

245 - 285 Million Years

Carboniferous

285 - 360 Million Years

Devonian

360 - 408 Million Years

Silurian

408 - 438 Million Years

Ordovician

438 - 500 Million Years

Cambrian

500 - 550 Million Years

Pre-Cambrian

550 Million - 4.8 Billion Years

For a much more concise time chart please visit the U.C. Berkeley website.