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Cambrian 570-500 MYA
A dramatic burst of evolutionary changes on Earth known as the "Cambrian Explosion". Animals evolved during this period, some of them were chordates, arthopods, ancestord of spiders, insects and crustaceans. The climate was generally cold but became warmer as the glaciers rececded. At that time Rodinia was coming apart. -
Ordovician 488.3- 443.7 MYA
In the north tropics the area was almost entirely ocean. The weather was warm and the atomsphere contsined a lot of misture. But the supercontinent started to move to the South Pole and massive glaciers formed forcing sea levels to drop. This sudden change caused a mass extinction within the small life forms that were living in the water. -
Silurian 443- 416 MYA
In this time the melting of large glaciers which contributed to substantial levels to rise in major seas. Coral reefs made their first appearance within this time and also the evolution of fishes. There was the first known fresh water fish and jawed fish. During this period there is the first evidence of life on land according to fossils. -
Devonian 416-358 MYA
The supercontinent, Gondwana, occupied the Southern Hemisphere, sea levels were high. Armored fish go extinct, but abundance of several species of fish. Earliest amphibians and ammonites. -
Carboniferous 345- 280 MYA
Abundant sharks and amphibians. Large swamps and coal forming forests. Earliest reptiles. Scale trees and seed ferns. -
Permian 280-225 MYA
The extinction of many types of marine animals including trilobites. Reptiles becoming bigger. -
Triassic 225-195 MYA
The earliest dinosaurs, abundant cycads and conifers. -
Jurassic 195-136 MYA
The earliest birds and mammals evolved. There were abundant dinosaurs and ammonites. Lush vegitation. -
Cretaceous 136-65 MYA
The earliest flowering plants, climax of dinosaurs followed byb their extinction. Great decline of brachiopods. There was an abundance of bony fish -
Tertiary 65-1.8 MYA
The earliest placental amimlas and modern mammals, large running mammals and also ice ages. -
Quaternary 1.8 MYA- Present
Large carnivors and neanderthals dominated the Earth. The begining of humans and also there were mastodons. Ice age.
