The geologic time scale By Jenae_2 4600 BCE Eon: Archean 2500 BCE Eon: Proterozoic 544 BCE Eon: Phanerozoic Era: Paleozoic Period: Cambrian 489 BCE Period: Ordovician 433 BCE Period: Silurian 418 BCE Period: Devonian 360 BCE Period: Carboniferous 300 BCE Period: Permian 253 BCE Era: Mesozoic Period: Triassic 200 BCE Period:Jurassic 144 BCE Period: Cretaceous 65 BCE Era: Cenozoic Period: Tertiary Epoch: Paleocene 55 BCE Epoch: Eocene 34 BCE Epoch: Oligocene 23 BCE Epoch: Miocene 5 BCE Epoch: Pliocene 2 BCE Period: Quaternary Epoch: Pleistocene 1 BCE Epoch: Holocene