Geologic Timescale Timeline Project

  • precambrian

    10 The presence of stromatolites that shallow seas covered much of earth during intervals in this period.11 Nearly half of the mineral deposits in the world occur in the rocks of this period.
  • Period: to


    geological timescale
  • cambrian

    22 Trilobites appear. 23 Shelled brachipods appear.
  • ordovician

    1 There is very little plant life during this period. 30 Colonies of tiny vertertebrates called graptolites flourished and vertebrates appear, fish did not have jaws or teeth and their bodies were covered with bony plates.
  • silurian

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

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

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

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

    8 Appalachian Mountains are created because of the collision of tectonic plates and savannahs form. 38 Environmental change causes mass extinction of sea invertebrates ( trilobites and eurypterids) as the seas retreat.
  • Triassic

    16 Welcome to the world of dinosaur! Enter the squirrel sized dinosaur and first forest dwelling mammals appear. 34 Ichthyosaurus are living in the ocean, new invertebrates called ammonite develop.
  • Jurassic

    3 Flying reptiles pterosaurs are in the air now. 13 Whoa these dinos are getting big and dominate the land - lizards hipped and bird hipped appear - carnivores and herbivores have arrived.
  • Cretaceous

    5 First flowering plants appear - angeosperm. 35 Impact hypothesis - dinosaur mass extinction.
  • Paleocene

    12 First primates evolve. 29 Small rodents evolve.
  • Eocene

    17 Flying squirrels, whales, and bats appear. 25 World wide temperatures drop by about 4 degrees Celcius (39.2 degrees Fahrenheit).
  • Oligocene

    6 Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding. 27 Many early mammals become extinct, clams and snails flourish.
  • Miocene

    32 Antarctic ice caps begin to form. 36 Mediterranian sea dries up and refills several times due to tectonic forcesa and dropping sea levels.
  • Pliocene

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

    9 Homosapiens (modern humans) appear and are hunters. 20 Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf and giant ground sloth).
  • Holocene

    19 The last glacial period ended and sea levels rose, great lakes formed. 28 Modern human developed agriculture and used tools made up of bronze and iron.
  • Anthropocene

    7 Some scientists believe that humankind has caused mass extinctions of plant and animal species, polluted the oceans, and altered the atmosphere. 14 There is argument as to when this epoch began, some scientists think t began with the industrial age in the early 1800s. Others think it began with the atomic age in the 1950s.