Geological Time Chart
(Evolution of major groups of animals)
| Era |
Period |
Epoch |
Million Years |
Organisms evolved |
|
Coenozoic |
Quaternary |
Holocene |
0.01-0 |
Dominance of man. Domestication of animals and agriculture. Modern genera and species evolved. Last ice age 30-40 thousand years ago. Woolly mammoth extinct. |
|
Pleistocene |
1.5-0.1 |
Mass extinction. Huge floods. Ice age. Many large mammals extinct. Mastodons and woolly mammoth extinct. Prehistoric man evolved. Cave paintings. |
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|
Tertiary |
Pliocene |
6-1.5 |
Dry climate. Oceans shrink. Mammals increase specialization. Mountains rise. First hominids appear. First orchids. |
|
|
Miocene |
23-6 |
Ice age. First man-like apes. Evolution of apes, monkeys, horse, elephant. Radiation of grazing mammals. Huge grasslands. All grass subfamilies distinct. |
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|
Oligocene |
37-23 |
Archaic mammals attain their maximum diversity. Creodonts (archaic carnivores) appear. First apes. Origin of grasslands. |
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|
Eocene |
53-37 |
Forests of monocotyledons and flowering plants appear. Ancestors of horse, camel, elephant appear. First bats. |
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|
Paleocene |
65-53 |
Climate warm. Vegetation abounds. Ancestors of most modern mammals appear. Insectivores abundant. First grasses, Rhododendrons, whales and rodents. |
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|
Mesozoic |
Cretaceous |
135-65 |
Mass extinction. 60% of tetrapod families extinct. Himalayas, Andes, Alps arise. Dinosaurs and Ammonites extinct. First monocotyledons. First marsupials and placental mammals (Pantotheres). First flowering plants. Climate cool. Angiosperms radiate. |
|
|
Jurassic |
205-135 |
First bird, Archaeopteryx. Dominance of dinosaurs. Earliest mammals. Dicotyledons and conifers common. Continents become high. Origin of insect pollinators. |
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|
Triassic |
250-205 |
Massextinction. 80% of tetrapod families extinct. Continental drift begins. Arid conditions. Gymnosperms dominate. First dinosaurs.Mammal-like reptiles. First teleosts, first crocodiles and first flying reptiles. |
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|
Palaeozoic |
Permian |
290-250 |
Mass extinction. 70% of tetrapod families extinct. Single land mass, Pangaea and single ocean. Continents rise. Glaciations set in. Expansion of reptiles, origin of Cotylosauria and Therapsida. Last trilobites. |
|
|
Carbonife- rous |
Pennsylva- nian |
290 |
Warm and humid climate. Swamps abundant. First modern soils. First reptiles. Sharks abundant. First mammal-like reptiles. Earthworms. |
|
|
Mississipp- ian |
350 |
Forests of ferns and gymnosperms. Foraminiferans and shell-crushing sharks abound. First winged insects. Radiation of amphibians. Little seasonal variations. |
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|
Devonian |
410-350 |
Mass extinction. Arid climate. First gymnosperm forests. First amphibians (Labyrinthodonts). First spiders. Dominance of fishes. First ferns. First vascular plants. First insects. |
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|
Silurian |
440-410 |
Algae dominate. Land plants definite. Trilobites decline. First scorpions and millipedes appear. First fishes, ostracoderms and placoderms appear. |
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|
Ordovician |
510-438 |
Land submerged. Warm climate. Algae abound. Plants invade land. First corals. First vertebrates. Cephalopods and snails. First Agnatha. |
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|
Cambrian |
600-510 |
Mass extinction. Mild climate. Marine algae. Many invertebrates. Trilobites. Brachiopods. Sponges. Molluscs. Explosion after mass extinction. |
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|
Proterozoic |
3,500-600 |
Primitive aquatic algae and fungi. Annelid burrows. Protozoa. Oxygenation of atmosphere. Prokaryote radiation. Skeleton of sponges. |
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|
Archeozoic |
4,600-3,500 |
Calcareous deposits by algae. Origin of life. Fossils of cyanobacteria. |
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|
Solar |
5,000-4,600 |
Formation of Solar system. Strong solar wind. Formation of primitive atmosphere on earth. |
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|
Cosmic |
20,000-5,000 |
Big Bang and matter synthesis. |