Timetoast Geology Timeline By kmacumber Jan 1, 1923 Cambrian Earliest record of marine life - Trilobites are dominant. Period: Jan 1, 1923 to Jan 1, 1971 Paleozoic Jan 1, 1934 Ordovician Jan 1, 1941 Silurian Jan 1, 1950 Devonian Jan 1, 1961 Carboniferous Jan 1, 1971 Permian Jan 1, 1976 Triassic Jan 1, 1986 Jurassic Jan 1, 1999 Cretaceous Jan 1, 2010 Tertiary Apr 18, 2010 Quaternary
