• Some important events in Earth’s History in years ago

     

    PRECAMBRIAN Age: 4, 600 million to 540 million years ago

    1.       4.6 billion years ago                Earth forms

    2.       3.8 billion                  Earth’s crust now solid: oldest rocks

    3.       3.4 billion                 oldest fossils  (algae and bacteria in the oceans)

    4.       3.0 billion                        photosynthesis begins in the oceans

    5.       2.0 billion                        cells with a nucleus

    6.       1.8 billion                        free oxygen in the atmosphere

    7.       1.0 billion                        multi-cell organisms form in the ocean

    8.       600 million         -     invertebrates form 

    PALEOZOIC Era: 545 million to 245 million years ago

    9.     545 million               Cambrian explosion: fossils with shells

    10.     510 million                       first fish (first vertebrates)

    11.     440 million                       first land plants

    12.     360 million                      first insects and coal-forming forests

    13.     320 million                      first reptiles

    14.     250 million                      mass extinction of almost all life

    MESOZOIC ERA: 245 million to 65 million years ago

    15      245 million                      dinosaurs evolve, Pangaea starts to break up

    16.      240 million                       mammals evolve

    17.     145 million                       first flowering plants

    18.     65 million                        dinosaurs extinct

    CENOZOIC ERA: 65 million years ago to the present

    19.     30 million                        mammals and flowering plants abundant

    20.     4 to 5 million                   first human like ancestors

    21.      200,000 years                homo sapiens evolve (us)

    22.     17,000                            end of the last ice age/ Lenape in NJ

    23.     10,000 years                   recorded history begins

    24.     40 years                         humans first explore the Moon

     

    Precambrian means “before the Cambrian”.

    Paleozoic means “ancient life”.

    Mesozoic means “middle life”.

    Cenozoic means “recent life”.

     

     
Last Modified on February 14, 2020