-
570 million years - 225 million years
The first era of Earth, periods consisted of: Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian. -
-
570 million years - 500 million years
Earliest abundant record of marine life, trilobites are dominant. -
500 million years - 435 million years
Earliest fishes, invertebrates dominant, coelentrates and mollusks become abundant, echinoderms expand in numbers and kinds. -
435 million years - 395 million years
Earliest terrestrial plants and animals, peak development of eurypterids. -
395 million years - 345 million years
Earliest amphibians and ammonites, extenction of armored fishes, many fishes abundant. -
345 million years - 280 million years
Earliest reptiles, great coal forming forests, sbundant sharks and amphibians, large and numerous scale trees and seed ferns. -
280 million yers - 225 million years
Extinction of many kinds of marine animals, including the trilobites, little change in terrestrial animals. -
225 million years - 65 million years
The second era of earth, it consisted of the Triassic, Jurassic and Cretaceous. -
225 million years - 195 million years
Earliest dinosaurs, abundant cycades and conifers. -
195 million years - 136 million years
Earliest birds and mammals, abundant dinosaurs and ammonites. -
136 million years - 65 million years
Earliest flowering plants, climax of dinosaurs and ammonies followed by extinction, great decline of brachiopods, great development of bony fish. -
65 million years - present
The era we are in now. -
65 million years - present
Humans, mastadons, mammoths, large carnivores, abundant grazing animals, large running mammals, many modern types of mammals, earliest placental mammals. -
The period of now
