Geologic Timeline

  • Precambrian

    EVENT 10 The presence of stromatolites indicate that shallow seas covered much of Earth during intervals in this period. EVENT 11 Nearly half of the valuable mineral deposits in the world occur in the rocks of this period.
  • Cambrian

    Cambrian
    EVENT 22 Trilobites appear. EVENT 23 Shelled brachiopods appear.
  • Ordovician

    Ordovician
    EVENT 1 There is very little plant life during this period. EVENT 30 Colonies of tiny invertebrates call Graptolites flourished and vertebrates appear, Fish did not have jaws or teeth and their bodies were covered with body plates.
  • Silurian

    Silurian
    EVENT 24 Eurypterids (sea scorpions), sea stars and coral become more common. EVENT 33 Vascular land plants and animals, such as scorpions begin to evolve on land.
  • Devonian

    Devonian
    EVENT 31 Huge plants begin to develop,early amphibians form. EVENT 37 Age of Fishes,fish that can breath out of the water and spend time on land form.
  • Mississippian

    Mississippian
    EVENT 2 Swamps and forests cover the land. EVENT 21 Early reptiles resembling large lizards appear.
  • Pennsylvanian

    Pennsylvanian
    EVENT 4 Giant cockroaches appear. EVENT 15 Coal deposits form.
  • Permian

    Permian
    EVENT 8 Appalachian Mountains are created because of the collision of tectonic plates & Savannahs form. EVENT 38 Environmental change causes mass extinction of sea invertibrates (trilobites & Eurypterids) as the seas retreat.
  • Triassic

    Triassic
    EVENT 16 Dinosaur had formed. Squirrel sized dinosaur & the first forest dwelling mammals appear. EVENT 34 Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop.
  • Jurassic

    Jurassic
    EVENT 3 Flying reptiles called pterosaurs are in the air now. EVENT 13 Whoa those dinosaur are getting big & dominate the land-Lizard- hipped and bird- hipped appear- carnivores and herbivores have arrived.
  • Cretaceous

    Cretaceous
    EVENT 5 First flowering plants appear- angiosperm. EVENT 35 Impact hypothesis- dinosaur mass extinction.
  • Palaocene

    Palaocene
    EVENT 12 First primates evolve. EVENTS 29 Small rodents evolve.
  • Eocene

    Eocene
    EVENT 17 Flying squirrels, whales, and bats appear. EVENT 25 World wide temperature drop about 4 degrees Celsius (39.2 degrees Fahrenheit.)
  • Oliogocene

    Oliogocene
    EVENT 6 Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasion continent colliding. EVENT 27 Many early mammal become extinct, clams and snails flourish.
  • Miocene

    Miocene
    EVENT 32 Antarctic icecaps begin to form. EVENT 36 Meditterian sea dries up and refills several times due tectonic forced dn dropping sea levels.
  • Pliocene

    Pliocene
    EVENT 18 Various species migrated between continents across land bridges. EVENT 26 First modern horse appear.
  • Pleistocene

    Pleistocene
    EVENT 9 Homosapien (modern humans) appeared & are hunters. EVENT 20 Specie that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (wolf & giant ground sloth.)
  • Holocene

    Holocene
    EVENT 7 Some scientist believe that humans kind has caused mass extinction of the plants and animals species, polluted the oceans and altered the atmosphere. EVENT 14 There is argument as to when this epoch began, some scientist think that it begin with the industrial age in the early 1800's other think it began with the atomic age in the 1950's.
  • Anthropocene

    Anthropocene
    EVENT 19 The last glacial period ended and sea levels rose, Great lakes formed. EVENT 28 Modern humans developed agriculture and used tools made of bronze and iron.