Geologic Timescale

  • Cambrian Period 570-500 MYA

    Cambrian Period 570-500 MYA
    It is the time when most of the major groups of animals first appear in the fossil record. Anthropods, trilobites and sponges were around.Climate went from cold to warmer. Mass extinction from advancing glaciers lowering temperatures and loss of oxygen in water. Animals that couldn't adapt went extinct.
  • Ordovician 500-435 MYA

    Ordovician 500-435 MYA
    Diverse marine invertabretes and red and green algae. Lots of moisture in the mild climate. Again the end was caused by glaciers causing seas and taking away 60% of invertibrates. 25% of all families went extinct.
  • Silurian 435-395 MYA

    Silurian 435-395 MYA
    Rise in major seas from melting glaciers. Coral reefs made first showing. Evolution of fish occured. First fish with jaws and first fish in freshwater occur. First spiders and centipedes.
  • Devonian 395-345 MYA

    Devonian 395-345 MYA
    Two major lines of vascular plants started to evolve. First radiation of plants is what started the time period. Seed plants appeared towards end and so did the first forests.
  • Carboniferous 345-280 MYA

    Carboniferous 345-280 MYA
    Start of coal bearing layers. Birds, reptiles and mammals started reproducing due to amniote eggs. Appalachin mountains were formed. Lime incrusted green algae was formed.
  • Permian 280-225 MYA

    Permian 280-225 MYA
    The largest mass extinction recorded in the history of life on Earth. It affected marine communities the most by far.Modern conifers, the most familiar gymnosperms of today, first appear in the fossil record of the Permian. the motion of the Earth's crustal plates had brought much of the total land together.
  • Triassic 225-195 MYA

    Triassic 225-195 MYA
    Time of transition.It was at this time that the world-continent of Pangaea existed. Organisms of the Triassic are considered to belong to one of three groups the holdovers from the Permo-Triassic extinction, new groups, and other new groups which went on to dominate the Mesozoic world.
  • Jurrasic 195-136 MYA

    Jurrasic 195-136 MYA
    First birds, dinasaurs, and lots and lots of fish. Rocks found between France and Switzerland. Made the Jurrasic park movie off of it.
  • Cretaceous 136-65 MYA

    Cretaceous 136-65 MYA
    Last portion of age of dinosaurs. Many of first bird insects were found during this time. Many primary animals died leaving the way for secondary animals to take over.
  • Tertiary 65-1 MYA

    Tertiary 65-1 MYA
    Tectonic plates caused lands to move. Antartica went to South Pole. Temperatures slowly cooled. Mammals replaced reptiles. Birds stuck around and plants flourished
  • Quaternary 1 MYA-Present

    Quaternary 1 MYA-Present
    They say an ice age is coming? its starting now. Present day weather and animals.