Adaptation and Natural Selection

Geological Time Divisions

---

For most non-specialists, geological time divisions are hard to memorize. Here is a rough table.

ERA	YEARS AGO	PERIOD	EPOCH	FEATURES
Cenozoic 新生代	10000 to 65 million	Quaternary第四紀	Recent現世	modern humans
			Pleistocene更新世	ice ages
		Tertiary 第三紀	Pliocene鮮新世	mountain uplift
			Miocene中新世	ape
			Oligocene漸新世	sabertoothed tigers
			Eocene始新世	modern mammals and birds
			Paleocene暁新世	age of mammals begins
Mesozoic 中生代	65 million to 230 million	Cretaceous白亜紀		last dinosaurs
		Jurassicジュラ紀		dinosaurs
		Triassic三畳紀		age of reptiles
Paleozoic 古生代	230 million to 570 million	Permianペルム紀		conifer forests
		Carboniferous石炭紀		age of amphibians
		Devonianデボン紀		age of fishes
		Silurianシルル紀		shellfish
		Ordovicianオルドビス紀		primitive fishes
		Cambrianカンブリア紀		various marine invertebrates
Precambrian	570 million to 5 billion	Proterozoic		bacteria
		Archeozoic

webmaster