Class Copy

Geologic Time

Eon Era Period Epoch Time (mya) Notable Events
Phanerozoic Cenozoic Neogene (Quaternary) Holocene Today Interglacial warming. The "anthropocene". 6th mass extinction.
Pleistocene 1.6 Ice age. Large mammal forms appear. In NA extinction of large mammals. Homo habilis to Homo sapiens.
Paleogene (Tertiary) Pliocene 5.3 Isthmus of Panama allows Great American Interchange, changes ocean currents. Cascades form. Cooler and drier climate. Camels, horses and ground sloths in North America (NA). Australopithecus.
Miocene 24 Mediterranean dries up. Climate cooler. Grasslands replace forests. Modern mammals, birds and whales. Substantial primate evolution.
Oligocene 37 Active tectonics. Grasslands expand. Modern mammal groups dominate. Archaic mammals disappear. Modern whales. Primates in NA.
Eocene 58 Climate subtropical and moist in NA. Early whales, horses, camels, rhinos, bats evolve.
Paleocene 66 Continental seas dry up. Mammals diversify.
Mesozoic Cretaceous 144 Continents shaped as today. Rockies form. Warm climate. Dinosaurs dominate. First flowering plants. Mass extinction
Jurassic 208 Pangaea breaks up. Dinosaurs dominant on land. Conifers and ginkgoes widespread. First birds and lizards.
Triassic 245 Early dinosaurs. Marine reptiles evolve. First mammals. First crocodiles. Mass extinction: 50% of marine organisms go extinct.
Paleozoic Permian 286 Pangaea forms. Reptiles forms expand. Flies and beetles appear. Gymnosperms appear and replace coal-era plants. Greatest mass extinction - 95-99% of all life disappears; the end of the trilobites.
Carboniferous Pennsylvanian 320 Winged insects diversify. First reptiles. Amphibians common. Highest oxygen levels.
Mississippian 360 Large trees appear. Coastal swamps create coal forming beds. Climate cools.
Devonian 408 Europe and NA collide forming the Appalachians. The age of fish. Arthropods and amphibians on land. First ferns, seed-bearing plants and "forests". Mass extinction.
Silurian 438 NA near equator. Jawed fishes. Vascular land plants. First sharks.
Ordovician 505 First land plants. Invertebrates diversify. Vertebrates appear. Armored and bony fishes. NA covered by shallow seas. First mass extinction (49%)
Cambrian 570 Gondwana emerges. Cambrian explosion of complex life forms. Trilobites.
Proterozoic 2500 Eukaryotes appear. Oxygen catastrophe. Multi-cellular organisms. Snowball Earth.
Archaean 3800 Rodinia supercontinent. First life (prokaryotes). Stromatolites.
Hadean 4600 Formation of Earth. Formation of moon.