paleozoic

  • Jan 8, 1111

    the start

    multicelled animals underwent a dramatic "explosion" in diversity, and almost all living animal phyla appeared within a few millions of years
  • Jan 8, 1112

    Cambrian Period (542 to 488.3 mya)

    Cambrian Period (542 to 488.3 mya)
    Almost every metazoan phylum with hard parts, and many that lack hard parts, made its first appearance in the Cambrian.
  • Jan 8, 1113

    Tommotian Stage (534 to 530 mya)

    Tommotian Stage (534 to 530 mya)
    • Animals with shells appeared Solar brightness was 6% less than today.
  • Jan 8, 1114

    Ordovician Period (488.3 to 443.7 mya)

    Ordovician Period (488.3 to 443.7 mya)
    • diverse marine invertebrates, such as trilobites, became common
      • First vertebrates appear in the ocean.
      • First green plants and fungi on land.
      • Fall in atmospheric carbon dioxide.
      • 450 mya: Start of Andean-Saharan ice age.
      • 443 mya: Glaciation of Gondwana.
      • Mass extinction of many marine invertebrates. Second largest mass extinction event. 49% of genera of fauna disappeared.
  • May 8, 1115

    Silurian Period (443.7 to 416 mya)

    Silurian Period (443.7 to 416 mya)
    • 420 mya: End of Andean-Saharan ice age.
      • Stabilization of the earth's climate
      • Coral reefs appeared
      • First fish with jaws - sharks
      • Insects (spiders, centipedes), and plants appear on land
  • May 8, 1116

    Devonian Period (416 to 359.2 mya)

    Devonian Period (416 to 359.2 mya)
    • Ferns and seed-bearing plants (gymnosperms) appeared
      • Formation of the first forests
      • Earth day is ~21.8 hours long.
      • Wingless insects appeared on land
      • 375 mya: Vertebrates with legs, such as Tiktaalik appeared.
      • Atmospheric oxygen level is about 16%
      • First amphibians appear
      • 374 mya: * Mass extinction of 70% of marine species. This was a prolonged series of extinctions occurring over 20 million years. Evidence of anoxia in oceanic bottom waters, and global cool
  • May 8, 1117

    Carboniferous Period (359.2 to 299 mya)

    Carboniferous Period (359.2 to 299 mya)
  • May 8, 1118

    Mississippian Epoch (359.2 to 318.1 mya)

    • 350 mya: Beginning of Karoo ice age.
      • Large primitive trees develop
      • Forests consist of ferns, club mosses, horsetails, and gymnosperms.
      • Oxygen levels increase
      • Vertebrates appear on land
      • First winged insects.
      • Seas covered parts of the continents
      • Animals laying amniote eggs appear (318 mya)
  • May 8, 1119

    Pennsylvanian Epoch (318.1 to 299 mya)

    • 310 mya: First reptiles
      • Atmospheric oxygen levels reach over 30%
      • Earth day is ~22.4 hours long. The Moon is 375,000 km from Earth.[31]
      • Giant arthropods populate the land
      • Transgression and regression of the seas caused by glaciation
      • Deposits of coal form in Europe, Asia, and North America
  • May 8, 1120

    Permian Period (299 to 251 mya)

    • 275 mya: Formation of the supercontinent Pangea
  • May 8, 1121

    Permian Period (299 to 251 mya)

    • Conifers and cycads first appear
      • Earth is cold and dry
      • Sail-backed synapsids like Edaphosaurus and Dimetrodon appeared
      • 260 mya: End of Karoo ice age.
      • 251 mya: * Mass extinction (Permian-Triassic)
      • Possible 480km-wide meteor crater in the Wilkes Land region of Antarctica [26]
      • Period of great volcanism in Siberia releases large volume of gases (CO2, CH4, and H2S) [8]
      • Oxygen (O2) levels dropped from 30% to 12% Carbon dioxide (CO2) level was about 2000 ppm E