Geologic Timescale

Eons

Longest segments of the geologic timescale

Divided from Eons

Eras

Divided from eras

Periods (most common)

Divided from periods

Epochs

Divided from epochs

Ages

Precambrian eon (or supereon)

Phanerozoic, Proterozoic, Archean, Hadean EONS

Phanerozoic ERAS

Cenozoic (recent life), Mesozoic (middle life), Paleozoic (ancient life)

Paleozoic Periods

Permian, Carboniferous (miss or Pennsylvanian), Devonian, Silurian, Ordovician, Cambrian

PERIODS of the Mesozoic and Cenozoic ERAS

Quaternary, neogene, paleogene, Cretaceous, Jurassic, Triassic

EPOCHS of Cenozoic era

Holocene (entirely new), pleistoncene (mostly new), Pliocene (more new), Miocene (less new), oligocene (few new), Eocene (dawn of the new), Paleocene (ancient new)