SILURIAN
DEVONIAN
CARBONIFEROUS
TRIASSIC
CRETACEOUS
PALEOGENE
JURASSIC
TERTIARY
QUATERNARY
CENOZOIC
EARLY
EARLY CENOZOIC
MIOCENE
CAMBRIAN
MESOPROTEROZOIC
ARCHEAN
PALEOPROTEROZOIC
PALEOZOIC
MESOZOIC
PRECAMBRIAN
NEOPROTEROZOIC
EARLY CAMBRIAN
ORDOVICIAN
PERMIAN
MIDDLE
LATE
MIDDLE MESOPROTEROZOIC
LATE MESOPROTEROZOIC
NEOGENE
EARLY PALEOPROTEROZOIC
EARLY CRETACEOUS
PALEOARCHEAN
MESOARCHEAN
NEOARCHEAN
EARLY MESOPROTEROZOIC
MIDDLE PALEOPROTEROZOIC
LATE PALEOPROTEROZOIC
HOLOCENE
LATE TRIASSIC
PALEOCENE
EOCENE
PLIOCENE
PLEISTOCENE
LATE JURASSIC
LATE PALEOZOIC
LATE CARBONIFEROUS
EARLY CARBONIFEROUS
MIDDLE JURASSIC
LATE CRETACEOUS
EARLY TRIASSIC
MIDDLE TRIASSIC
EARLY PERMIAN
MISSISSIPPIAN
LATE DEVONIAN
OLIGOCENE
MIDDLE MESOZOIC
PENNSYLVANIAN
LATE CENOZOIC
EARLY MESOZOIC
LATE MESOZOIC
EARLY JURASSIC
PROTEROZOIC
EARLY PALEOZOIC
EARLY ORDOVICIAN
MIDDLE PALEOZOIC
EARLY DEVONIAN
MIDDLE DEVONIAN
CENOMANIAN
SANTONIAN
MIDDLE ORDOVICIAN
LATE ORDOVICIAN
EARLY SILURIAN
MIDDLE CENOZOIC
CAMPANIAN
PHANEROZOIC
LATE PERMIAN
LATE EOCENE
RECENT
LATE PROTEROZOIC
RIPHEAN
VENDIAN
LATE RIPHEAN
MIDDLE RIPHEAN
ALBIAN
MAASTRICHTIAN
DANIAN
EARLY RIPHEAN
MIDDLE CAMBRIAN
EARLY TERTIARY
LATE CAMBRIAN
EOARCHEAN
LATE SILURIAN
EARLY MISSISSIPPIAN
MIDDLE PENNSYLVANIAN
LATE MISSISSIPPIAN
MIDDLE MISSISSIPPIAN
LATE TERTIARY
JURRASSIC
MIDDLE JURRASSIC
TURONIAN
EARLY PENNSYLVANIAN
LATE PENNSYLVANIAN
MIDDLE SILURIAN
CONIACIAN
HAUTERIVIAN
MIDDLE PROTEROZOIC
LATE ARCHEAN