Eon Era Period Sub-Period Epoch Ma*
  Phanerozoic Cenozoic Neogene Holocene
0.01
Pleistocene
1.8
Pliocene
5.3
Miocene
23
Paleogene Oligocene
33.9
Eocene
55.8
Paleocene
65.5
Mesozoic Cretaceous
145.5
Jurassic
199.6
Triassic
251
Paleozoic Permian
299
Carboniferous Pennsylvanian
318.1
Mississippian
359.2
Devonian
416
Silurian
443.7
Ordovician
488.3
Cambrian
542
Precambrian Proterozoic
2500
Archean
not
defined