Earth's Geologic History By kkbliss Oct 1, 1923 Cambrian Oct 1, 1934 Ordovician Oct 1, 1941 Silurian Oct 1, 1950 Devonian Oct 1, 1961 Carboniferous Oct 1, 1971 Permian Oct 1, 1976 Triassic Oct 1, 1986 Jurassic Oct 1, 1999 Cretaceous Oct 2, 2010 Tertiary Jan 2, 2011 Quaternary
