Geological Timescale

By J0shuax
  • Period: to

    J Armestar Perioid 3

    Geological Timescale

  • Precambrian #1 Event:19

    The presence of stromatolites indicates that shallow seas covered much of Earth during intervals in this period.

  • Precambrian #2

    Nearly half of the valuable mineral deposits in the world occur in the rock in this period

  • Cambrian #1 Event:18

    Trilobites Appear

  • Cambrian #2

    Shelled brachiopods appear

  • Ordovician #1 Event:17

    There is very little plant life during this period

  • Ordovician #2

    Colonies of tiny invertebrates call graptolites flourished and vertebrates appear, fish did not have jaws or teeth and their bodies were covered with bony plates