Eons			Eras	Periods		Epochs
Phanerozoic			Cenozoic	Quaternary		Holocene or Recent
						Pleistocene
				Tertiary	Neogene	Pliocene
						Miocene
					Paleogene	Oligocene
						Eocene
						Paleocene
			Mesozoic	Cretaceous
				Jurassic
				Triassic
			Paleozoic	Permian
				Carboniferous	Pennsylvanian
					Mississippian
				Devonian
				Silurian
				Ordovician
				Cambrian
Precambrian	Proterozoic	Cryptozoic
	Archean
	Hadean