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Period: to
Cambrian Period (570-500 MYA)
-Triolovites were dominant.
-All of the eath was oceans with growing granite continents.
-All life was marine life. -
Period: to
Ordovician Period (500-435 MYA)
-Earliest fishes appear
-Invertebraets are the dominant species
-Molusks become abundant -
Period: to
Silurian Period (435-395 MYA)
-Earliest terrestrial (land) animals
-Earliest development of euryplerids -
Period: to
Devonian Period (395-345 MYA)
-Earliest amphibians and ammonites
-Extinction of armored fishes -
Period: to
Carboniforous Period (345-280 MYA)
-Earliest reptiles
-Great coal forming forests flourished
-Sharks and amphibians were abundant at this time
-Large number of scale trees and seed ferns -
Period: to
Permian Period
-Extinction of any kinds of marine animals, including trilobites
-Little change in terrestrial animals -
Period: to
Triassic Period (225-195 MYA)
-Earliest dinosaurs
-Abundant cycades and conifers -
Period: to
Jurassic Period (195-136 MYA)
-Earliest birds and mammals apear at this time
-Dinosaurs were the domant species -
Period: to
Cretacious Period (136-65 MYA)
-Earliest flowering plants
-Climax of the dinosaurs and ammonites--followed by their extinction
-Great decline of brachiopods
-Great development of bony fishes -
Period: to
Tertiary Period (65 MYA-Present day)
-Humans, mastodons, and mamoths roam the earth
-Abundance of grazing animals and large running mammals
-Earliest placental mammals exist