Geologic Time Line

  • First Known Animals

    1 Billion Years Ago
    ~ These are more advanced forms of algae and a wide variety of protozoa.
    ~ Large mountain chains form as the continents collide.
    ~ Plate tectonics slows to approximately the same rate as the present.
  • Beginning of Paleozoic Era And Cambrian Period

    543 Million Years Ago
    ~ Rodinia begins to break up into northern and southern portions.
    ~ The global climate is generally mild.
    ~ Plant life is limited to marine algae.
  • Beginning of Ovdovician Period

    490 Million Years Ago
    ~ The barren continents of Laurentia, Baltica, Siberia, and Gondwana are separated by large oceans.
    ~ Shallow seas cover much of North America at the beginning of the period.
    ~ As the seas recede, they leave a thick layer of limestone.
  • Beginning of Silurian Period

    443 Million Years Ago
    ~ The North American, European, and Asian land masses are situated on or near the equator.
    ~ Laurentia and Baltica collide.
    ~ Gondwana sits in the south polar region.
  • Beginning of Devonian Period

    417 Million Years Ago
    ~ Europe and North America collide, forming the northern part of the ancestral Appalachian mountain range.
    ~ Africa and South America are positioned over the South Pole.
    ~ The climate is generally warm and moist
  • Beginning of Mississippian Period (need info)

    354 Million Years Ago
  • Beginning of Pennsylvanian Period

    323 Million Years Ago
    ~ Two major land masses form: Laurasia and Gondwana
    ~ Coal-forming sediments are laid down in vast swamps.
    ~ Global climatic changes occur, changing from warm and wet to cooler and drier.
  • Beginning of Permian Period

    290 Million Years Ago
    ~ A single supercontinent, Pangaea, forms as Earth's landmasses collide and merge.
    ~ Extensive glaciation persists in what is now India, Australia, and Antarctica.
    ~ Hot, dry conditions prevail elsewhere on Pangaea, and deserts become widespread.
  • Beginning of Mesozoic Era and Triassic Period

    248 Million Years Ago
    ~ The general climate is warm, becoming semiarid to arid.
    ~ The Triassic Period, unlike the previous periods, is marked by few significant geologic events.
    ~ Pangaea covers nearly a quarter of the Earth's surface.
  • First Bird (Pic and info)

    225 Million Years Ago
  • Beginning of Jurassic Period

    206 Million Years Ago
    ~ The supercontinent of Pangea begins to breakup as North America separates from Eurasia and Africa.
    ~ The Atlantic Ocean begins to form.
    ~ Reptiles adapt to life in the sea, in the air, and on land. Dinosaurs are the dominant reptile on land
  • First Mammals

    200 Million Years Ago
    ~ Mammals are vertebrates.
    ~ These early mammals were small and furry and looked a lot like modern mice.
    ~ Despite these many mammal-like characteristics, it is thought they still laid leathery eggs.
  • Beginning of Cretaceous Period

    144 Million Years Ago
    ~ The continents—while not in their current positions on the Earth—are shaped much as they are today.
    ~ South America and Africa separate, and the Atlantic ocean widens.
    ~ A circum-equatorial sea, Tethys, forms between the continents of the Northern and Southern Hemisphere.
  • Beginning of Cenozoic Era and Paleocene Epoch

    65 Million Years Ago
    ~ During the Paleocene, the vast inland seas of the Cretaceous Period dry up, exposing large land areas in North America and Eurasia.
    ~ Australia begins to separate from Antarctica, and Greenland splits from North America.
    ~ A remnant Tethys Sea persists in the equatorial region.
  • Beginning of Eocene Epoch

    55 Million Years Ago
    ~ Plate tectonics and volcanic activity form the Rockies in western North America.
    ~ Continental collisions between India and Asia culminate in the Alpine-Himalayan mountain system.
    ~ Antarctica and Australia continue to separate and drift apart.
  • Beginning of Oligocene Epoch

    34 Million Years Ago
    ~ Tectonic plate movement is still very dynamic
    ~ Africa and Europe nearly collide, closing the Tethys Sea and leaving as a remnant the Mediterranean Sea.
    ~ Volcanism and fragmentation of western North America is associated with the emplacement of major ore deposits.
  • Beginning of Miocene Epoch

    24 Million Years Ago
    ~ Modern ocean currents are essentially established.
    ~ A drop in sea level near the end of the Epoch isolates and dries up the Mediterranean Sea, leaving evaporite deposits on its floor.
    ~ The climate is generally cooler than the Oligocene Epoch.
  • Beginning of Pliocene Epoch

    Beginning of Pliocene Epoch
    5 Million years ago
    ~ Both marine and continental faunas were essentially modern,
    ~ In North America, rodents, large mastodonts and gomphotheres, and opossums continued successfully, while hoofed animals (ungulates) declined,
    ~ Alligators and crocodiles died out in Europe as the climate cooled
  • Hominid Footprints in Footprint Tuff

    Hominid Footprints in Footprint Tuff
    3 Million Years Ago
    ~ hominin footprints, preserved in volcanic ash
    ~ Laetoli was first recognized by western science in 1935 through a man named Sanimu
    ~ hominid fossil footprints, discovered in 1976 by Mary Leakey
  • Beginning of The Pleistocene Epoch

    Beginning of The Pleistocene Epoch
    2 Million Years ago.
    ~ The Pliocene was named by Sir Charles Lyell.
    ~ It is the second and youngest epoch of the Neogene Period in the Cenozoic Era.
    ~ During the Pliocene epoch climate became cooler and drier,
  • Today.

    Now Tehe
    ~ We have tvs
    ~Cell Phones
    ~ Touch Boards