Geologic Time Scales

Eras of the Earth
Precambrian
Paleozoic Era
Cambrian Period
Ordovician Period
Silurian Period
Devonian Period
Carboniferous Period
Mesozoic Era
Triassic Period
Jurassic Period
Cretaceous Period
Cenozoic Era
Tertiary Period
Quaternary Period
Geologic Timeline


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Geologic Time Scales

Eras of the Earth

Paleontologist have divided Earth's history into eras, periods, and epochs. Monumental events and changes mark the end of one time frame, and the beginning of another. The Precambrian is the first time frame in Earth's history, begining with the birth of the Earth, and ending with an event called the "Cambrian Explosion". An abundance of diverse life found in the Burgess Shell marks the Cambrian Explosion. This explosion was latter seen to be less of a sudden increase in families, and marked more by extraordinarily good conditions for the formation of fossils. Still, that early exclamation still lives with us today. The Cambrian Explosion begins the Paleozoic Era which saw the evolution of mulicellular organisims, and the evolution of shells. The Paleozoic Era ended with a mass exticntion caused by the impact of a comet or asteroid 250mya. The exit of the Paleozoic Era herladed the begining of the The Mesozoic Era, which saw the rise and fall of the dinosaurs. Both dinosaurs and the Mesozoic Era ended when another comet struck the Earth 65mya. This event rose the curtain on the Cenozoic Era, the age of mammals, birds, bony fish, and flowering plants.What event will end the Cenozioc?