Geologic Time Scale

By rash

  • Cambrian 570-500 MYA

    Cambrian period, beggining of pelozoic, first time multicellulas life forms flourished on Earth.

  • Ordovicain 500-435 MYA

    Echinoderms (starfish, sand dollar, sea urchin and sea cucumbers.) Invertebrates are dominant, mollusks become abundant. Earliest fish are jawless and later, jawed and armored fish.

  • Silurian 435-395 MYA

    Earliest terrestrial plants and animals Tiktalik Eurypterids develop.

  • Devonian 395-345 MYA

    Armored fish go extinct, but abundance of several species of fish. Earliest amphibians and ammonites.

  • Carboninferous 345-280 MYA

    Abundant sharks and amphibians, Large swamps and coal forming forests. Earliest reptiles. Scale trees and seed ferns.

  • Permian 280-225 MYA

    Extinction of many types of marine animals including trilobites.

  • Triassic 225-195 MYA

    Earliest dinosaurs, abundant cycads and conifers.

  • Jurassic 195-136 MYA

    Earliest birds and mammals, abundant dinosaurs and ammonites.

  • Cretaceous 136-65 MYA

    Earliest flowering plants, climax of dinosaurs, followed by their extinction. Great decline of branchiopads. Abundance of bony fish.

  • Tertiary 65-1.8 MYA

    Earliest placental mammals, modern mammals, large running mammals.

  • Quaternary 1.8- Present

    Large carnivores, neanderthals, humans, mastodons