3 Eras of the Phanerozoic
3.1 Paleozoic Era
3.1.1 Cambrian Period
3.1.2 Ordovician Period
3.1.3 Silurian Period
3.1.4 Devonian Period
3.1.5 Carboniferous Period
3.1.6 Permian Period
3.2 Mesozoic Era
3.2.1 Triassic Period
3.2.2 Jurassic Period
3.2.3 Cretaceous Period
3.3 Cenozoic Era
3.3.1 Paleogene Period
3.3.2 Neogene Period
3.3.3 Quaternary Period