Geologic Timeline- Courtni Pawlak

By pawlacou
  • 500 BCE

    Cambrian Period 570-500 MYA

    Cambrian Period 570-500 MYA
    Trilobites were dominant, earliest record of marine life
  • 435 BCE

    Ordovician 500-435 MYA

    Ordovician 500-435 MYA
    Echinoderms (starfish, sand dollars, sea urchins, and sea cucumbers). Invertebrates are dominant, mollusks become abundant. Earliest fish that are jawless and later, jawed and armored fish.
  • 395 BCE

    Silurian 435-395 MYA

    Silurian 435-395 MYA
    Earliest terrestrial plants and animals. Tiktaalik Eurypterids develop.
  • 345 BCE

    Devonian 395-345 MYA

    Devonian 395-345 MYA
    Armored fish go extinct, but there's an abundance of several species of fish. Earliest amphibians and ammonites.
  • 299 BCE

    Carboniferous 359-299 MYA

    Carboniferous 359-299 MYA
    Many swamps on land and sponge reefs in the oceans. Reptiles appear. Early winged insects and cockroaches appear.
  • 251 BCE

    Permian 299-251 MYA

    Permian 299-251 MYA
    Amphibians dominate the land. Early cone-bearing plants like pine trees appear. Period ends with the largest mass extinction known with 95% of all marine species and 50% of all animals going extinct.
  • 195 BCE

    Triassic 225-195 MYA

    Triassic 225-195 MYA
    Earliest dinosaurs. Abundant cycads and conifers.
  • 136 BCE

    Jurassic 195-136

    Jurassic 195-136
    Earliest birds and mammals. Abundant dinosaurs and ammonites.
  • 65 BCE

    Cretaceous 136-65 MYA

    Cretaceous 136-65 MYA
    Earliest flowering plants. Climax of dinosaurs followed by their extinction. Great decline of brachiopods. Abundance of bony fish. Extinction of 65% of species including the dinosaurs.
  • 1 BCE

    Tertiary 65-1.8 MYA

    Tertiary 65-1.8 MYA
    Earliest placental mammals, modern mammals, large running mammals.
  • 1 BCE

    Quaternary 1.8- Present

    Quaternary 1.8- Present
    Large carnivores, Neanderthals, humans, and mastodons.