Subdivisions of eons based on major geological events, such as the appearance of new species or mass extinctions. The Phanerozoic Eon is divided into three eras: Paleozoic, Mesozoic, and Cenozoic.
Subdivisions of eons based on major geological events, such as the appearance of new species or mass extinctions. The Phanerozoic Eon is divided into three eras: Paleozoic, Mesozoic, and Cenozoic.