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Important Dates and Cool Creatures in Earth History

Time LinesNumbers shown for eons, periods, and epochs in the following list are in millions of years before the present, and are based on the International Stratigraphic Commission's latest time chart. Eons are the largest subdivisions of time, then periods, then epochs. Relative ages of important dates and creatures are also in millions of years before the present.

Links to references for material in this list can be found at the KGS earth history web site.

Hadean time

(beginning of Precambrian time)

Archean Eon (From oldest rocks on earth to 2,500 million years ago)

Proterozoic Eon (2,500 to 542 million years ago)

(latter part of Precambrian time)

Phanerozoic Eon (542 million years ago to the present)

Paleozoic Era (542 million to 245 million years ago)

Cambrian Period (542 to 488 million years ago)

Ordovician Period (488 to 443 million years ago)

Silurian Period (443 to 416 million years ago)

Devonian Period (416 to 359 million years ago)

Carboniferous Period (European term which equals the combined Mississippian and Pennsylvanian Periods in the United States )

Mississippian Period (359 to 318 million years ago)

Pennsylvanian Period (318 to 299 million years ago)

Permian Period (299 to 251 million years ago)

Mesozoic Era "Age of Reptiles" (251 to 65.5 million years ago)

Triassic Period (251 to 199 million years ago)

Jurassic Period (199 to 145.5 million years ago)

Cretaceous Period (145.5 to 65.5 million years ago)

Cenozoic Era "Age of Mammals" (65.5 million years ago to the present)

Tertiary Period (65.5 to 1.81 million years ago). In Europe the beginning of the Cenozoic Era is called the Paleogene Period (65.5 to 23.03 million years ago)

Paleocene Epoch (65.5 to 55.8 million years ago)

Eocene Epoch (55.8 to 33.9 million years ago)

Oligocene Epoch (33.9 to 23.03 million years ago)

In Europe , the latter part of the Cenozoic is called the Neogene Period (23.03 to the present)

Miocene Epoch (23.03 to 5.33 million years ago)

Pliocene Epoch (5.33 to 1.81 million years ago)

Quaternary Period (1.81 million years ago to the present)

Pleistocene Epoch (1.81 to 0.015 million years ago)

Holocene Epoch (0.015 million or 15,000 years ago to the present)

List compiled by Stephen Greb, Kentucky Geological Survey


Go to Images in Time for pictures of ancient creatures
Go to Key Links in Earth History for more info and images about earth history

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