geologic time scale

  • Cambrian Period 570-500 MYA

    Earliest Marine Life recorded. Abundent amount of Trilobites
  • Ordovidan 500-435 MYA

    Echinoderms ( Starfish, Sand dollar , sea urchin and sea cucumbers). Invertebrates are dominant, mollusks become abundant. Earliest Fish that are Jawless and later, jawed and armored fish.
  • Silurian 435M-395M

    Earliest terrestrial plants and animals. Tiktaalik
    Eurypterids develop
  • devonian 359M-354M

    Armored fish go extinct, but abundance of several species of fish. Earliest amphibians and ammonites.
  • Carbonian 345M-280M

    Abundant sharks and amphibians. Large swamps and coal forming forests. Earliest reptiles. Scale trees and seed ferns
  • Permian 280M-225M

    Extinction of many types of marine animals including trilobites.
  • Triassic 225M-195M

    Earliest Dinosaurs, abundant cycads and conifers
  • Jurassic 195M-136M

    Earliest birds and mammals abundant dinosaurs and ammonites
  • Cretaceous 136M-65M

    Earliest flowering plants, climax of dinosaurs followed by their extinction. Great decline of brachiopods. Abundance of bony fish.
  • Tertiary 65M-1.8M

    Earliest Placental Mammals, modern mammals, large running mammals
  • Quaternary 1.8M-Present

    Large Carnivores, Neanderthals, Humans, mastodons