| Eon Phanerozoic Precambrian |
| Era Cenozoic Mesozoic Paleozoic Proterozoic Archaeozoic |
| Period Quaternary Tertiary Cretacious Jurassic Triassic Permian Carboniferous Devonian Silurian Ordovician Cambrian Vendian Riphean Aphebian |
| Epoch Holocene Pleistocene Pliocene Miocene Oligocene Eocene Paleocene Upper Lower Upper Middle Lower Upper Middle Lower Pennsylvanian Mississippian |
| Geologic Time Scale |
| The top most is the recent, going to down is to the past. Eons are the largest units of geologic time units, and those are divided by eras, which are divided by periods, which are divided by epochs. |
Geology ---------------- |
| Years Ago (Started) - 0.011 Million 1.64 Million 3.6 Million 5.2 Million 7.1 Million 11.2 Million 14.8 Million 16.4 Million 20.5 Million 23.5 Million 28.5 Million 35.5 Million 37 Million 41.3 Million 49 Million 56.5 Million 57.9 Million 61 Million 65 Million 71.3 Million 83.5 Million 85.8 Million 89 Million 93.5 Million 99 Million 122 Million 121 Million 127 Million 132 Million 137 Million 144.2 Million 151 Million 154 Million 159 Million 164 Million 169 Million 176 Million 180 Million 190 Million 195 Million 202 Million 208 Million 210 Million 221 Million 227 Million 234 Million 242 Million 245 Million 248 Million 290 Million 323 Million 362.5 Million 408 Million 439 Million 510 Million 570 Million 610 Million 1650 Million 2500 Million 3.5 Billion (Beginning of Earth) |
| Age Piacenzian Zanclean Messinian Tortonian Serravallian Langhian Burdigalian Aquitanian Chattian Rupelian Priabonian Bartonian Lutetian Ypresian Thanetian Selandian Danian Maastrichtian Campanian Santonian Coniacian Turonian Cenomanian Albian Aptian Barremian Hauterivian Valanginian Berriasian Tithonian Kimmeridgian Oxfordian Callovian Bathonian Bajocian Aalenian Toarcian Pliensbachian Sinemurian Hettangian Rhaetian Norian Carnian Ladinian Anisian Olenekian Induan |