87% 4.6 Precambrian

 Earth was completely molten  No water  No atmosphere  No land  No life

 An object the size of Mars crashes into the still molten earth.  Material ejected by the impact went into orbit around the earth.  This material coalesced and formed the moon.

bombardment from space

 A time of dramatic geological, climatic, and evolutionary change  Divided into 6 periods:  Cambrian  Ordovician  Silurian  Devonian  Carboniferous  Permian

 543 Million years ago  Marked the beginning of the Paleozoic Era  A time when most of the major groups of animals first appear in the fossil record.  This was accompanied by a major diversification of other organisms.

trilobite

invertebrates

land plants

fish

amphibians

swamps

Swamps

swamps

 Permian Mass Extinction  Mass extinction 245 million years ago  95% of all marine species became extinct

87% 4.6 Precambrian Cambrian Devonian Permian Swamps

 The Age Of Reptiles  Divided into 3 Periods:  Triassic  Jurassic  Cretaceous

earliest dinosaurs

Swamps

first birds

earliest mammals

Swamps

 The Mesozoic Era ended with the extinction of dinosaurs 65 million years ago  70% of all plants, animals, and reptiles perished

Swamps

 The Age of Mammals  Divided into 2 periods:  Tertiary  Quaternary

Swamps

mammals thrive

Swamps

land mammals dominate

earliest humans did not arise until approximately 200,000 years ago