-
Cambrian 570-500 MYA
earliest abundant record of marine life trilobites dominant -
Period: to
Paleozoic
-
Ordovician 500-435 MYA
*Earliest fishes
*Invertabrates dominant
*coelenterates and mollusk become abundant
*Echinoderms expand in numbers and kinds -
Sulrian 435-395 MYA
*Earliest terrestrial plants and animals
*Peak devlopment of eurypterids -
Devonian 395-345 MYA
Earliest amphibians and ammonites
*extinction of armored fishes, many fishes are abundant -
Carboniferous 345-280 MYA
*Earliest reptiles
*Great cole-forming forest
*Abundant sharks and amphibians
*Large and numerous scale trees and seed ferns -
Permian 280-225 MYA
*Extinction of many kinds of marine animals, including trilobites
*Little change in terrestrial animals -
Triassic 225-195 MYA
*Earliest dinosuars
*Abundant cycedes and conifers -
Jurassic 195-136 MYA
*Earliest birds and mammals
*Abundant dinosuars and ammonites -
Cretaceous 136-65 MYA
*Earliest flowering plants
*Climax of dinosuars and ammonites - followed by extinction
*Great decline of brachiopods
*Great devolpment of bony fishes -
Tertiary 65-Present MYA
*Humans, mastodons, mammoths and large carnivores
*abundant grazing animals
*Large running mammals
*Many modern types of mammals
*Earliest placental mammals
