The Archean Eon was followed by the Proterozoic Eon, each billions of years; then the Paleozoic: the Cambrian’s seventy million years, the Ordovician’s sixty million years, the Silurian’s forty million years, the Devonian’s fifty million years, the Carboniferous’s sixty-five million years, and the Permian’s fifty-five million years; then the Mesozoic: the Triassic’s thirty-five million years, the Jurassic’s fifty-eight million years, and the Cretaceous’s seventy million years; then the Cenozoic: the Tertiary’s 64.5 million years and the Quaternary’s 2.5 million years.
The Flow Chart of Earth
