The Geologic Column

By Astrid Paola
  • Hadean
    20 BCE

    Hadean

    Formation of earth (unihabitable). It was Approximate assumed over 4,000,000,000 years ago.
  • Archean
    19 BCE

    Archean

    Earth become habitable; spontaneous generation of first cells; rise of bacteria and cyanobacteria (blue-green algae). It was Approximately assumed about 4,000,000,000 years ago.
  • Proterozoic
    18 BCE

    Proterozoic

    Simple multicellular sea creatures develop; algae and plankton develop; eukaryotic cells develop. It was Approximately assumed 2,500,000,000 years ago.
  • Cambrian
    17 BCE

    Cambrian

    Sudden explosion of life; trilobites dominant; rise of other marine invertebrates; some vertebrates. It was Approximate assumed 542,000,000 years ago.
  • Ordovician
    16 BCE

    Ordovician

    Trilobites abundant; vertebrates increase. It was Approximate assumed 488,300,000 years ago.
  • Silurian
    15 BCE

    Silurian

    Land colonized by arthropods and plants. It was Approximate assumed 443,700,000 years ago.
  • Devonian
    14 BCE

    Devonian

    First amphibians; freshwater fish; winged insects. It was Approximate assumed 416,000,000 years ago.
  • Mississippian
    13 BCE

    Mississippian

    Amphibians; freshwater fish; wingless insects. It was Approximate assumed 359,200,00 years ago.
  • Pennsylvanian
    12 BCE

    Pennsylvanian

    Giant insects; first reptiles. It was Approximate assumed 318,100,000 years ago.
  • Permian
    11 BCE

    Permian

    Modern insects; reptiles spread; evergreens; extinction of trilobites. It was Approximate assumed 299,000,000 years ago.
  • Triassic
    10 BCE

    Triassic

    First dinosaurs; rise of mammal-like reptiles. It was Approximate assumed 251,000,000 years ago.
  • Jurassic
    9 BCE

    Jurassic

    Giant dinosaurs; early birds; first modern mammals.It was Approximate assumed 199,600,000 years ago.
  • Cretaceous
    8 BCE

    Cretaceous

    Mass extinction (including dinosaurs); flowering plants appear. It was Approximate assumed 145,500,000 years ago.
  • Paleocene Epoch
    7 BCE

    Paleocene Epoch

    Early mammals become dominant; rise of modern birds. It was Approximate assumed 65,500,000 years ago.
  • Eocene Epoch
    6 BCE

    Eocene Epoch

    First Horses. It was Approximate assumed 55,800,000 years ago.
  • Oligocene Epoch
    5 BCE

    Oligocene Epoch

    Primitiv apes; whales; first modern mammals. It was Approximate assumed 33,900,000 years ago.
  • Miocene Epoch
    4 BCE

    Miocene Epoch

    Rise of grazing mammals. It was Approximate assume 23,000,000 years ago.
  • Pliocene Epoch
    3 BCE

    Pliocene Epoch

    Peak of mammals; modern invertebrates. It was Approximate assumed 5,300,000 years ago.
  • Pleistocene Epoch
    2 BCE

    Pleistocene Epoch

    Ice Age(s); mass extinctions; rise man. It was approximate assumed 1,800,000 years ago.
  • Recent (Holocene) Epoch
    1 BCE

    Recent (Holocene) Epoch

    End of last Ice Age; rise of human civilization.