geological time-scale

By 0607155253

  • precambrian time

    1. nearly half of the valuable mineral deposits in the world occur in the rocks 10.The presence of stromatolites indicates that shallow seas covered much of Earth during intervals in this period
  • Period: to

    R.Oviedo p.7

    geological time scale

  • cambrian

    22.Trilobites appear
    23.Shelled brachiopods appear

  • ordovician

    1. Shelled brachiopods appear
    2. 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

  • silurian

    1.Eurypterids (sea scorpions), sea stars and coral become more common
    2.Vascular land plants and animals, such as scorpions begin to evolve on land

  • devonian

    1.Huge plants begin to develop, early amphibians form
    2.Environmental change causes mass extinction of sea invertibrates (trilobites & eurypterids) as the seas retreat

  • mississippian period

    1.Swamps and forests cover the land
    2.Early reptiles resembling large lizards appear

  • pennsylvanian period

    1.Giant cockroaches appear
    2.Coal deposits form

  • permian

    1.Appalachian Mountains are created because of the collision of tectonic plates & savannahs form
    2. Environmental change causes mass extinction of sea invertibrates (trilobites & eurypterids) as the seas retreat

  • triassic

    1. Welcome to the world of the Dinosaur! Enter the squirrel sized dinosaur & the first forest dwelling mammals appear
    2. Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop

  • jurassic

    1. Flying reptiles called pterosaurs are in the air now
    2. Whoa those dinos are getting big & dominate the land - Lizard-hipped and bird-hipped appear - carnivores and herbivores have arrived

  • cretaceous

    1. First flowering plants appear - angiosperm
    2. Impact hypothesis - dinosaur mass extinction

  • paleocene

    1. First primates evolve
    2. Smalll rodents evolve

  • eocene

    1.Flying squirrels, whales and bats appear
    2. World wide temperatures drop about 4 degrees celsius (39.2 degrees fahrenheit)

  • oligocene

    1. Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding 2.Many early mammal become extinct, clams and snails flourish

  • miocene

    1.Antarctic icecaps begin to form
    2.Mediterranean Sea dries up and refills several times due to tectonic forcesa dn dropping sea levels

  • pliocene

    1. Various species migrated between continents across land bridges
    2. First modern horses appear

  • pleistocene

    1. Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf & giant ground sloth)
    2. Homosapien (modern humans) appeared & are hunters

  • holocene

    1. The last glacial period ended and sea levels rose, Great Lakes formed
    2. Modern human developed agriculture and used tools made of bronze and iron

  • anthropocene

    1. Some scientists believe that human kind has caused mass extinctions of plant and animal species, polluted the oceans and altered the atmosphere
    2. There is argument as to when this epoch began, some scientist think it began with the industrial age in the early 1800's other think it began with the atomic age in the 1950's