Geologic timeline Alexis By alexisleann Sep 17, 1925 Cambrian 570m - 500m First time multi-cellular life forms flourished on Earth. Earliest record of life. Trilobites were dominant. Sep 17, 1936 Ordovician 500m - 435m Invertebrates were dominant. Sep 17, 1943 Silurian 435m - 395m Sep 18, 1952 Devonian 395m - 345 m Sep 18, 1963 Carboniferous 345m - 280m Sep 18, 1973 Permian 280m - 225m Sep 18, 1978 Triassic 225m - 195m Sep 18, 1988 Jurassic 195m - 139m Sep 18, 2001 Cretaceous 136m - 65m Sep 18, 2012 Tertiary 65m - 1.8m Sep 18, 2013 Quaternary 1.8m - Present
