Geological Eras

Era	Period
quaternary	12,000bc - present
pleistocene	600,000bc - 12,000bc
tertiary	65,000,000bc - 600,000bc
pilocene	10,000,000bc - 600,000bc
miocene	25,000,000bc - 10,000,000bc
oligocene	35,000,000bc - 25,000,000bc
eocene	55 000,000bc - 35 000,000bc
paleocene	65,000,000bc - 55,000,000bc
mesozoic	230,000,000bc - 65,000,000bc
cretaceous	135,000,000bc - 65,000,000bc
jurassic	180,000,000bc - 135,000,000bc
triassic	230,000,000bc - 180,000,000bc
plaezoic	4,500,000,000bc - 230,000,000bc
carboniferous II	300,000,000bc - 230,000,000bc
carboniferous I	345,000,000bc - 300,000,000bc
devonian	405,000,000bc - 345,000,000bc
silurian	425 000,000bc - 405 000,000bc
ordovician	500,000,000bc - 425 000,000bc
cambrian	600,000,000bc - 500,000,000bc
precambrian II	2,000,000,000bc - 600,000,000bc
precambrian I	4,500,000,000bc - 2,000,000,000bc