Timeline of Geologic Eons, Eras, Periods and Epochs

Geologic Time:

NOTE: Names and ages vary from source to source, this is a synthesis. For example, the Hadean, Archean and Proterozoic Eons were once all just called "Precambrian" -- a term still sometimes encountered, along with the ill-defined "Protocambrian" and "Eocambrian".

EONS
• Hadean Eon 4.5 to 3.8 Billion Years Ago
• Archean Eon 3.8 to 2.5 Billion Years Ago
  ERAS
  • Paleoarchean 3.8 to 3.3 Billion Years Ago
  • Mesoarchean 3.3 to 2.9 Billion Years Ago
  • Neoarchean 2.9 to 2.5 Billion Years Ago
• Proterozoic Eon 2.5 Billion to 570 Million Years Ago
  ERAS
  • Paleoproterozoic 2.5 Billion to 1.6 Billion Years Ago
  • Mesoproterozoic 1.6 Billion to 900 Million Years Ago
  • Neoproterozoic 900 to 570 Million Years Ago
    Periods
    • Not clearly defined yet, terms like Ediacaran (or Ediacarian), Vendian, Verangian are used.
• Phanerozoic Eon 570 Million Years Ago to Present
  ERAS
  • Paleozoic 570 to 245 Million Years Ago
    Periods
    • Cambrian 544 to 490 Million Years Ago
      EPOCHS
      • Early Cambrian 544 to 510 Million Years Ago
        AGES
        • Manykaian (or Nemakit-Daldynian) 544 to 530 Million Years Ago
        • Tommotian 530 to 525 Million Years Ago
        • Atdbanian 525 to 520 Million Years Ago
        • Botomian (or Toyonian or Lenian) 520 to 510 Million Years Ago
      • Middle Cambrian 510 to 500 Million Years Ago
        AGE
        • Solvan (or Manevian)
      • Late Cambrian 500 to 490 Million Years Ago
        AGES
        • Dresbachian (or Maentwrogian)
        • Franconian (or Dolgellian)
        • Trempealeauan
    • Ordovician 490 to 440 Million Years Ago
      Epochs
      • Early Ordovician
        AGES
        • Tremadocian 490 to 485 Million Years Ago
        • Arenigian 485 to 478 Million Years Ago
      • Middle Ordovician
        AGES
        • Llanvirnian 478 to 468 Million Years Ago
        • Llandeilian 468 to 458 Million Years Ago
      • Late Ordovician
        AGES
        • Caradocian 458 to 448 Million Years Ago
        • Ashgillian 448 to 440 Million Years Ago
    • Silurian 440 to 410 Million Years Ago
      EPOCHS
      • Early Silurian
        AGES
        • Llandoverian 440 to 428 Million Years Ago
        • Wenlockian 428 to 421 Million Years Ago
      • Late Silurian
        AGES
        • Ludlovian 421 to 414 Million Years Ago
        • Pridolian 414 to 410 Million Years Ago
    • Devonian 410 to 360 Million Years Ago
      EPOCHS
      • Early Devonian
        AGES
        • Gedinnian 410 to 401 Million Years Ago
        • Siegenian 401 to 394 Million Years Ago
        • Emsian 394 to 387 Million Years Ago
      • Middle Devonian
        AGES
        • Eifelian 387 to 380 Million Years Ago
        • Givetian 380 to 374 Million Years Ago
      • Late Devonian
        AGES
        • Frasnian 374 to 367 Million Years Ago
        • Famennian 367 to 360 Million Years Ago
    • Carboniferous
      EPOCHS
      • Mississippian 360 to 325 Million Years Ago (called Lower or Early Carboniferous in Europe)
        AGES
        • Tournaisian 360 to 352 Million Years Ago
        • Visean 352 to 333 Million Years Ago
        • Serpukhovian 333 to 325 Million Years Ago
      • Pennsylvanian 325 to 286 Million Years Ago (called Middle and Late, or Middle and Upper Carboniferous in Europe)
        AGES
        • Bashkirian (approximates Namurian?) 325 to 308 Million Years Ago
        • Moscovian (or Westphalian) 308 to 294 Million Years Ago
        • Kasimovian (or Gzelian or Stephanian) 294 to 286 Million Years Ago
    • Permian 286 to 245 Million Years Ago
      EPOCHS
      • Early Permian
        AGES
        • Asselian 286 to 279 Million Years Ago
        • Sakmarian 279 to 268 Million Years Ago
        • Artinskian 268 to 263 Million Years Ago
      • Late Permian
        AGES
        • Kungurian 263 to 258 Million Years Ago (sometimes considered Early Permian)
        • Kazanian (or Ufimian) 258 to 253 Million Years Ago
        • Tatarian 253 to 245 Million Years Ago
  ERAS
  • Mesozoic 245 to 65 Million Years Ago
    Periods
    • Triassic 245 to 208 Million Years Ago
      EPOCHS
      • Early Triassic
        AGE
        • Scythian 245 to 240 Million Years Ago
      • Middle Triassic
        AGES
        • Anisian 240 to 235 Million Years Ago
        • Ladinian 235 to 230 Million Years Ago
      • Late Triassic
        AGES
        • Carnian 230 to 225 Million Years Ago
        • Norian 225 to 208 Million Years Ago
    • Jurassic 208 to 146 Million Years Ago
      EPOCHS
      • Early Jurassic
        AGES
        • Hettangian 208 to 204 Million Years Ago
        • Sinemurian 204 to 198 Million Years Ago
        • Pliensbachian 198 to 193 Million Years Ago
        • Toarcian 193 to 187 Million Years Ago
      • Middle Jurassic
        AGES
        • Aalenian 187 to 183 Million Years Ago
        • Bajocian 183 to 176 Million Years Ago
        • Bathonian 176 to 169 Million Years Ago
        • Callovian 169 to 163 Million Years Ago
      • Late Jurassic
        AGES
        • Oxfordian 163 to 156 Million Years Ago
        • Kimmeridgian 156 to 152 Million Years Ago
        • Tithonian 152 to 144 Million Years Ago
    • Cretaceous 146 to 65 Million Years Ago
      EPOCHS
      • Early Cretaceous
        AGES
        • Berriasian 144 to 138 Million Years Ago
        • Valanginian 138 to 131 Million Years Ago
        • Hauterivian 131 to 124 Million Years Ago
        • Barremian 124 to 119 Million Years Ago
        • Aptian 119 to 113 Million Years Ago
        • Albian 113 to 97.5 Million Years Ago
      • Late Cretaceous
        AGES
        • Cenomanian (sometimes included with Early Cretaceous) 97.5 to 91 Million Years Ago
        • Turonian 91 to 88.5 Million Years Ago
        • Coniacian 88.5 to 87.5 Million Years Ago
        • Santonian 87.5 to 84 Million Years Ago
        • Campanian 84 to 74.5 Million Years Ago
        • Maastrichtian 74.5 to 66.4 Million Years Ago
  ERAS
  • Neozoic (also called Cenozoic) 66.4 Million Years Ago to Present
    Periods
    • Tertiary 65 to 1.8 Million Years Ago
      Epochs
      • Paleocene (first epoch of the Paleogene) 65 to 54 Million Years Ago
        AGES
        • Danian 66.4 to 63.6 Million Years Ago
        • Selandian 63.6 to 57.8 Million Years Ago
      • Eocene (second epoch of the Paleogene) 57.8 to 36.6 Million Years Ago
        AGES
        • Ypresian 57.8 to 52 Million Years Ago
        • Lutetian 52 to 43.6 Million Years Ago
        • Bartonian 43.6 to 40 Million Years Ago
        • Priabonian 40 to 36.6 Million Years Ago
      • Oligocene (last epoch of the Paleogene) 36.6 to 23.7 Million Years Ago
        AGES
        • Rupelian 36.6 to 30 Million Years Ago
        • Chattian 30 to 23.7 Million Years Ago
      • Miocene (first epoch of the Neogene) 23.7 to 5.3 Million Years Ago
        AGES
        • Aquitanian 23.7 to 21.5 Million Years Ago
        • Burdigalian 21.5 to 16.6 Million Years Ago
        • Langhian 16.6 to 15.1 Million Years Ago
        • Serravalian 15.1 to 11.2 Million Years Ago
        • Tortonian 11.2 to 6.5 Million Years Ago
        • Messinian 6.5 to 5.3 Million Years Ago
      • Pliocene (last epoch of the Neogene) 5.3 to 1.6 Million Years Ago
        AGES
        • Zanclean 5.3 to 3.4 Million Years Ago
        • Piacenzian 3.4 to 1.6 Million Years Ago
    • Quaternary 1.6 Million Years Ago to Present
      Epochs
      • Pleistocene 1.6 Million Years Ago to 11 Thousand Years ago
        AGE
        • Calabrian
      • Holocene 11 Thousand Years Ago to 1950
      • Anthropocene 1950 to present