The Geologic Column

By Astrid Paola
  • 20 BCE

    Hadean

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

    Archean

    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.
  • 18 BCE

    Proterozoic

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

    Cambrian

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

    Ordovician

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

    Silurian

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

    Devonian

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

    Mississippian

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

    Pennsylvanian

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

    Permian

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

    Triassic

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

    Jurassic

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

    Cretaceous

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

    Paleocene Epoch

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

    Eocene Epoch

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

    Oligocene Epoch

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

    Miocene Epoch

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

    Pliocene Epoch

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

    Pleistocene Epoch

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

    Recent (Holocene) Epoch

    Recent (Holocene) Epoch
    End of last Ice Age; rise of human civilization.