Dense metals sank to the centre of the Earth and formed the core, while the outside layer cooled and solidified to form the Earth's crust 4,500,000,000 years ago. Water vapour was released into the Earth's atmosphere through volcanism. It then cooled and formed the Earth's first oceans 4,400,000,000 years ago.
4600 mya - 570 mya
Consisted of the Periods:
Epoch / Age: Priscoan Period
Atmosphere and oceans form.
Oldest rocks form as Earth cools
Epoch / Age: N/A
Photosynthesizing cyanobacteria appear.
First unicellular life appear.
Epoch / Age: N/A
First soft-bodied animals appear.
First multicellular life appear.
570 mya - 245 mya
Consisted of the Periods:
Epoch / Age: Age of Invertebrates
End Botomain extinction event.
First fungi appear.
Trilobites are dominant.
Epoch / Age: Age of Invertebrates
Ordovician - Silurian extinction event.
First vertebrates appear.
Epoch / Age: N/A
First land plants appear.
First jawed fishes appear.
First insects appear.
Epoch / Age: Age of Fishes
Late Devonian extinction event.
First land animals appear.
First amphibians appear.
Epoch / Age: N/A
First reptiles appear.
First large cartilaginous fishes appear.
Epoch / Age: Age of Amphibians
Permian -Triassic extinction event.
Pangaea forms.
Epoch / Age: First Dinosaurs
Pangaea cracks.
First mammals appear.
Reptiles are dominant.
Epoch / Age: N/A
First Bird appear.
Pangaea splits into Laurasia, Godwanna.
Dinosaurs are dominant.
Epoch / Age: Extinction of Dinosaurs
K-T extinction event.
Earth looks closer to present-day.
Flowering plants appear.
Epoch / Ages:
65.5 mya - 57.8 mya
Paleocene: First large mammals appear.
57.8 mya - 36.6 mya
Eocene: Eocene - Oligocene extinction event.
36.6 mya - 23.7 mya
Oligocene: Mammals are dominant.
23.7 mya - 5.3 mya
Miocene: Grass becomes widespread
5.3 mya - 1.6 mya
Pliocene: Hominids (human ancestors) appear.
Epoch / Age:
1.6 mya - 0.01 mya
Pleistocene: Earliest Humans appear.
Ice Age begins
0.01 mya - Today
Holocene: Ice Age ends.
Humans are dominant.