______________ __________________ ______________

Hadean Precambrian 4.6-4.0 BYA

Archean Precambrian 4.0-2.5 BYA

Proterozoic Precambrian 2.5-542 MYA

Era Period Years Ago

______________ ______________ ______________

Paleozoic | Cambrian 542-488 MYA

|| Ordovician 488-443 MYA

|| Silurian 443-419 MYA

|| Devonian 419-359 MYA

|| Carboniferous 359-299 MYA

|| Permian 299-251 MYA

Mesozoic | Triassic 251-201 MYA

|| Jurassic 201-145 MYA

|| Cretaceous 145-66 MYA

Cenozoic | Paleogene 66-23 MYA

|| Neogene 23-2.5 MYA

|| Quaternary 2.5 MYA - present

MYA - Million years ago

BYA - Billion years ago