1) Distinct periods of history 2) Distinctive periods 3) Eocene and Miocene 4) Eocene and Miocene, for two 5) Eocene and neocene 6) Eocene and Pleistocene 7) Geochronological periods 8) Geologic periods 9) Geological period divisions 10) Geological periods 11) Geological times 12) Historical periods 1) Eras