Timeline of Earth's History

Time

Precambrian

542000000 - 4567000000

Eons

Phanerozoic Eon

0 - 542000000

Proterozoic Eon

542000000 - 2500000000

Archean Eon

2500000000 - 4000000000

Hadean Eon

4000000000 - 4567000000
  • 3000 mya: Atmosphere comprised of 75% nitrogen, 15% carbon dioxide.
  • 3500 mya: Prokarytoes (single-celled organisms) emerge
  • Around the same time, Cyanobacteria (first photosynthetic organisms) begin forming stromatolites

Eras

Cenozoic Era

0 - 65500000

Mesozoic Era

65500000 - 251000000

Paleozoic Era

251000000 - 542000000

Neoproterozoic Era

542000000 - 1000000000

Mesoproterozoic Era

1000000000 - 1600000000

Paleoproterozoic Era

1600000000 - 2500000000

Periods

Neogene Period

0 - 23030000

Paleogene Period

23030000 - 65500000

Cretaceous Period

65500000 - 145500000
  • Plate tectonics active during this period
  • 125mya: emergence of angiosperms (flowers, global warming, rise in carbon dioxide levels
  • 110mya: crocodiles emerge
  • 90mya: global warming ends
  • 65.5mya: MASS EXTINCTION: Large meteor impact in Mexico + excessive volcanic activity kill 80-90% of marine species and 85% of land - dinos extinct

Jurassic Period

145500000 - 199600000
  • 'Age of dinosaurs'
  • Warm earth w/ no polar ice, suited for dinos
  • Mammals mostly confined and small, hunted by dinos
  • giant herbivores and vicious carnivores are dominant
  • 166mya: evolutionary split between primitive mammals and monotremes
  • 150mya: first birds such as archaeopteryx
  • 148mya: evolutionary split between marsupials and eutharians

Triassic Period

199600000 - 251000000

-Pangea begins to break up
- Repopulation of earth by survivors of PT extinction
- Reptiles become dominant on land
- 240mya: sea-urchins appear
- 235mya: evolutionary split between dinosaurs and lizards
- First small dinosaurs emerge e.g. coelophysis
- 225mya: Adelobasileus proto-mammal emerged
- 205mya: first true mammals emerge
- 201mya: volcanism results in MASS EXTINCTION of 20% of all marine families

Permian Period

251000000 - 299000000
  • 275mya: formation of Pangea supercontinent
  • Conifers and cycads appear
  • Cold, dry earth
  • 260mya: end of Karoo ice age
  • 251mya: MASS EXTINCTION: permian-triassic: Earth's temp. increases, intense volcanism in Siberia 90% of oceanic and 70% of terrestrial flora/fauna extinct

Carboniferous Period

299000000 - 359200000

Devonian Period

359200000 - 416000000
  • ferns+seed-bearing plants emerge, first forests are formed
  • 400mya: terrestrial animals emerge along with wingless insects
  • Vertebrates with primitive legs emerge (e.g. Tiktaalik, a lobe-finned fish which was a transition between aquatic and terrestrial life)
  • First amphibians emerge
  • 374mya: MASS EXTINCTION: 70% of marine species over 20 million years - anoxia (depletion of oxygen) at depth in ocean, drop in temp.
  • 270mya: First trees appear

Silurian Period

416000000 - 443700000
  • 420mya: end of Andean-Saharan ice age and eventual stabilization of climate
  • terrestrial and marine plants reappear
  • first fish with jaws (sharks)
  • Insects (arachnids and centipedes)and plants appear on land

Ordovician Period

443700000 - 488300000
  • marine invertebrates become common e.g. Trilobites
  • photosynthetic green plants/fungi emerge on land for first time
  • 443mya: MASS EXTINCTION of marine invertebrates: 2nd largest, due to Andean-Saharan ice age (450)and glaciation of Gondwana, 49% of genera of fauna dissappear

Cambrian Period

488000000 - 542000000
  • 542mya: 'Cambrian explosion'; emergence and diversification of organisms
  • Most major groups of multicellular organisms emerge during this period of abundance of multicellular life

Ediacaran (Vendian) Period

542000000 - 630000000
  • 580mya: soft-bodied organisms emerge inc. Jellyfish, Tribrachidium, and Dickinsonia
  • 570mya: shelled invertebrates emerge at end of Stuartian-Varangian ice age

Cryogenian Period

630000000 - 850000000
  • 650mya: MASS EXTINCTION: 70% of marine flora dies because of global glaciation (cooling)

Tonian Period

850000000 - 1000000000
  • 1000mya: Multicellular organisms emerge

Stenian Period

1000000000 - 1200000000
  • 1100mya: Supercontinent Rodinia forms

Ectasian Period

1200000000 - 1400000000

Calymmian Period

1400000000 - 1600000000
  • Photosynthetic life proliferates
  • 1500mya: Eukaryotic cells emerge (cells with nucleus)

Statherian Period

1600000000 - 1800000000
  • Complex single-celled life emerges (1800-1600mya)

Orosirian Period

1800000000 - 2050000000

Rhyacian Period

2050000000 - 2300000000
  • 2200mya: organisms with mitochondria (aerobic respirators) emerge
  • 2100mya: Huronian Ice Age ends

Siderian period

2300000000 - 2500000000
  • Stable continents appear
  • 2500mya: free oxygen appears in atmosphere and oceans
  • 2400mya: Oxygen Catastrophe - Anaerobic organisms die out due to increased oxidation, banded iron formations created -2400mya: Huronian Ice Age starts

Stages/Epochs

Holocene Epoch

0 - 11400

Pleistocene Epoch

11400 - 2580000
  • Episodes of major global cooling
  • Hominids develop
  • 370,000ya: Human ancestors diverge with neanderthals
  • 160,000ya: Homo Sapiens emerge
  • 12,900ya: Comet explodes over Canada, American Megafauna made extinct

Pliocene Epoch

2580000 - 5300000

Miocene Epoch

5300000 - 23030000
  • 14mya: Warmer global climate leads to drying of continental interiors and formation of grassland in place of forest
  • 6mya: upright walking (bipedal) hominins emerge

Oligocene Epoch

23030000 - 33900000

Eocene Epoch

33900000 - 55800000
  • 50 mya: India collides with Asia, Himalayas formed
  • 45 mya: Australia separates from Antarctica
  • 45mya: modern mammals e.g. rhino, camel, horse appear
  • 34mya: global cooling forms permanent polar ice caps

Paleocene Epoch

55800000 - 65500000
  • 55.8mya: major global warming

Pennsylvanian Epoch

299000000 - 318100000
  • 300mya: first reptiles
  • Giant anthropods (w/ exoskeletons like crustacean, arachnid, insect) populate the land

Mississippian Epoch

318100000 - 359200000
  • Increased atmospheric oxygen
  • First land vertebrates appear
  • First winged insects
  • Amniote eggs (eggs enclosed by a shell) appear

Tommotian Stage

530000000 - 543000000
  • 510mya: oceanic vertebrates emerge