-
Cambrian
Earliest abundant record of marine life Trilobites dominant -
Ordovician
Invertebrates dominant
Coelenterates and mollusks become abundant -
Silurian
Earliest terrestrial plants and animals Peak development of euryplerids -
Devonian
Earliest amphibians and ammonites
Extinction of amored fishes, abundant fishes -
Carboniferous
Earliest reptiles
Abundant sharks and amphibians
Large and numerous scale trees and seed ferns -
Permian
Extinction of many kinds of marine animals, including trilobites -
Triassic
Earliest dinosaurs -
Jurassic
Earliest birds, and mammals -
Cretaceous
Earliest flowering plants
Climax of dinosaurs and ammonites followed by extinction -
Tertiary
Large running mammals
Many modern types of mammals
Abundant grazinf animals -
Quanternary
Humans
Mastodons
Mammoths
Large carnivores
