History of the Earth

  • 460

    Earth is created 4.6 BYA

  • Period: 460 to

    Earth's History

  • 470

    Earth's surface cooled to allow solid rocks 4 BYA

  • 480

    Cooled enough for water to be present 3.8 BYA

  • 495

    Unicellular prokaryotic organisms that resemble modern bacteria 3.5 BYA

  • 500

    Latest organisms were churning out oxygen 2.2 BYA

  • 510

    Prokaryotic cell begin evolving internal cell membranes 2 BYA

  • Jan 7, 800

    Precambrian Time-Few fossils exist from Precambrian time because the animals were all soft-bodied. Life existed only in the sea. 650-544 MYA

  • Jan 8, 1000

    PALEOZOIC ERA- 544-505 mya. Cambrian First time organisms have hard parts and first known representatives of most animal phyla evolved

  • Jan 9, 1150

    505-410 mya. Ordovician and Silurian Some arthropods become the first animals to live on land. First land plants evolved from aquatic ancestors.

  • Jan 10, 1300

    410-360 mya. Devonian Some plants adapted to drier areas and invaded more habitats. Insects appeared on land.The Devonian is often called the Age of Fishes because many groups of fishes were present in the oceans. Most fishes had jaws, bony skeletons, and

  • Jan 11, 1450

    360-245 mya. Carboniferous and Permian Reptiles evolved from certain amphibians. Winged insects evolved into many forms.Giant ferns and other plants formed vast swampy forests. Remains of ancient plants formed thick deposits of sediment that changed into

  • MESOZOIC ERA (The Age of Reptiles)-245-208 mya. Triassic Organisms that survived the Permian mass extinction became the main life forms early in the Triassic.These organisms included fishes, insects, reptiles, and cone-bearing plants.

  • 208-145 mya. Jurassic Dinosaurs became the dominant animals on land. One of the first birds, Archaeopteryx, appeared.Many paleontologists think that birds are close relatives of dinosaurs.

  • 145-65 mya. Cretaceous Dominant animals during this period included: reptiles, birds, turtles, crocodiles, fishes, and marine invertebrates. New forms of plant life included leafy trees, shrubs, and small flowering plants.

  • CENOZOIC ERA-65-1.8 mya. Tertiary The climate was generally warm and mild. Marine mammals such as whales and dolphins evolved. Grasses evolved, providing food for grazing mammals. Some mammals became very large, as did some birds.

  • 1.8-present Quaternary Earth’s climate cooled, causing a series of ice ages. About 20,000 years ago, Earth’s climate began to warm and sea levels began to rise. In the oceans, algae, coral, mollusks, fishes, and mammals thrived. Insects, birds, and land