-
255,000 BCE
Proterozoic
Simple multicellular sea creatures develop; algae and plankton develop; eukaryotic -
251,000 BCE
Mesozoic: Triassic
First dinosaurs; rise of mammal-like reptiles -
199,600 BCE
Mesozoic: Jurassic
Giant dinosaurs; early birds; first mammals -
180,000 BCE
Pleistocene Epoch
Ice Age(s); mass extinctions; rise of man -
145,000 BCE
Mesozoic: Cretaceous
Mass extinctions (including dinosaurs); flowering plants appear -
65,000 BCE
Tertiary: Paleocene Epoch
Early mammals become dominant; rise of modern birds -
55,800 BCE
Tertiary: Eocene Epoch
First horses -
54,200 BCE
Paleozoic: Cambrian
Sudden explosion of life; trilobites dominant; rise of other marine invertebrates; some vertebrates -
53,000 BCE
Tertiary: Pliocene Epoch
Peak of mammals; modern invertebrates -
48,830 BCE
Paleozoic: Ordovician
Trilobites abundant; vertebrates increase -
44,370 BCE
Paleozoic: Silurian
Land colonized by arthropods and plants -
41,600 BCE
Paleozoic: Devonian
First amphibians; freshwater fish; wingless insects -
40,000 BCE
Hadean
Formation of earth (uninhabitable) -
40,000 BCE
Archean
Earth becomes habitable; spontaneous generation of first cells; rise of bacteria and cyanobacteria -
35,920 BCE
Paleozoic: Mississipian*
Amphibians spread; sharks and bony fish; winged insects -
33,900 BCE
Tertiary: Oligocene Epoch
Primitive apes; whales; first modern mammals -
31,830 BCE
Paleozoic: Pennsylvanian*
Giant insects; first reptiles -
29,900 BCE
Paleozoic: Permian
Modern insects; reptiles spread; evergreens; extinction of trilobites -
23,000 BCE
Tertiary: Miocene Epoch
Rise of gazing mammals -
11,477 BCE
Quatenary: Recent (Holocene) Epoch
End of the last Ice Ace; rise of human civilization