Botkin Environmental Science Earth as Living Planet 8th txtbk

A-4 Appendix
D Geologic Time Scale and Biologic Evolution
Approximate Age in
Millions of Years
Era Before Present Period Epoch Life Form
Less than 0.01
Recent (Holocene)
0.01–2 Quaternary Pleistocene Humans
2
2–5 Pliocene
5–23 Miocene
Cenozoic 23–35 Tertiary Oligocene
35–56 Eocene Mammals
56–65 Paleocene
65
65–146 Cretaceous
Mesozoic 146–208 Jurassic Flying reptiles, birds
208–245 Triassic Dinosaurs
245
245–290 Permian Reptiles
290–363 Carboniferous Insects
Paleozoic 363–417 Devonian Amphibians
417–443 Silurian Land plants
443–495 Ordovician Fish
495–545 Cambrian
545
700 Multicelled organisms
3,400 One-celled organisms
4,000 Approximate age of oldest rocks
discovered on Earth
Precambrian
4,600 Approximate age of Earth and
meteorites
E Matter, Energy and Chemistry
Matter and Energy
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-
-
E mc
E m c -
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