17023681 abstract word cloud for geologic time scale with related tags and terms stock photo

geological timescale

  • Precambrian 4,600

    Precambrian 4,600
    EVENT 11-Nearly half of the value mineral deposits in the world occur in the rocks of this period.
    EVENT 22 Trilobites appear
  • Cambrian 542

    Cambrian 542
    EVENT 7-Some scientists believe that human kind has caused mass extinctions of plant and animal species, polluted the oceans and altered the atmosphere.EVENT 38.Environmental change causes mass extinction of sea invertibrates (trilobites & eurypterids) as the seas retreat.
  • Ordovician 488

    Ordovician 488
    EVENT 25.World wide temperatures drop about 4 degrees celsius (39.2 degrees fahrenheit). EVENT 30.Colonies of tiny invertebrates call graptolites florished and vertebrates appear, fish did not have jaws or teeth and their bodies were covered with bony plates.
  • Silurian 444

    Silurian 444
    EVENT 23.Shelled brachiopods appear. EVENT 24.Eurypterids (sea scorpions), sea stars and coral become more common.
  • Devonian

    Devonian
    EVENT 1. There is very little plant life during the period.
    EVENT 37. Age of fishes, fish that can breath out of the water and spend time on land form.
  • Mississippian period 359

    Mississippian period 359
    EVENT 2. Swamps and forests cover the land.
    EVENT 10.The presence of stromatolites indicates that shallow seas covered much of the earth during intervals in this period.
  • Pennsylvanian period 318

    Pennsylvanian period 318
    EVENT 4.Giant cockroaches appear.
    EVENT 15.Coal deposits form.
  • Permian 299

    Permian 299
    EVENT 30.Colonies of tiny invertebrates call graptolites florished and vertibrates appear, fish did not have jaws or teeth and their bodies were covered with bony plates. EVENT 19.The last glacial period ended and sea levels rose, great lakes formed.
  • Triassic 251

    Triassic 251
    EVENT 16.Welcome to the world of Dinosaur! Enter the squirrel sized dinosaur & the first forest dwelling mammals appear
    EVENT 34.Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop.
  • Jurassic 200

    Jurassic 200
    EVENT 3.Flying reptiles called pterosaurs are in the air now.
    EVENT 13.Whoa those dinos are getting big & dominate land - Lizard-Hipped and bird-hipped appear - carnivores and herbivores have arrived.
  • Cretaceous 146

    Cretaceous 146
    EVENT 33.Vascular land plants and animals, such as scorpions begin to evolve on land.
    EVENT 35.Impact hypothesis - dinosaur mass extinction.
  • Paleocene epoch 65.5

    Paleocene epoch 65.5
    EVENT 12.First primates evolve.
    EVENT 18.Various species migrated between continents across land bridges.
  • Eocene epoch

    Eocene epoch
    EVENT 17. Flying squirrels, whales and bats appear.
    EVENT 26.First modern horse appear.
  • Oligocene epoch 33.9

    Oligocene epoch 33.9
    EVENT 22.Trilobites appear.
    EVENT 19. The last glacial period ended and sea levels rose, Great Lakes formed.
  • Miocene epoch 23.0

    Miocene epoch 23.0
    EVENT 21.Early reptiles resembling large lizards appear.
    EVENT 25.World wide temperature drop about 4 degrees celsius (39.2 degrees fahrenheit)
  • Pliocene epoch 5.3

    Pliocene epoch 5.3
    5-First flowering plants appear - angiosperm
    20-Species that did not evolve to survive extreme cold moved to warmer climates areas or became extinct (dire wolf & giant ground sloth)
  • Holocene 0.0115

    Holocene 0.0115
    EVENT 6. Himalayas develop due to uplifting caused by the indian subcontinent and eurasian continents colliding.
    EVENT 9.Homosapien (modern humans) appeared & are hunters.
  • Pleistocene epoch 1.8

    Pleistocene epoch 1.8
    EVENT 32. Antarctic icecaps begin to form.
    EVENT 34. Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop.