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435 BCE
silurian 435-395 mya
The Silurian was a time when the Earth underwent considerable changes that had important repercussions for the environment and life within it.One result of these changes was the melting of large glacial formations. -
395 BCE
Devonian 395-345 mya
The vegetation of the early Devonian consisted primarily of small plants, the tallest being only a meter tall. By the end of the Devonian, ferns, horsetails and seed plants had also appeared, producing the first trees and the first forests. -
345 BCE
carboniferous 345-280 mya
The term Carboniferous comes from England, in reference to the rich deposits of coal that occur there. These deposits of coal occur throughout northern Europe, Asia, and midwestern and eastern North America. -
225 BCE
Triassic 225-195 mya
The Triassic Period was the first period of the Mesozoic Era and occurred between 251 million and 199 million years ago. It followed the great mass extinction at the end of the Permian Period and was a time when life outside of the oceans began to diversify. -
65
Tertiay 65-1.8 mya
The beginning of this period was very warm and moist compared to today’s climate. Much of the earth was tropical or sub-tropical. Palm trees grew as far north as Greenland! By the middle of the tertiary, during the Oligocene Epoch, the climate began to cool. This cooling trend continued and by the Pliocene Epoch an ice age had begun. -
136
cretaceous 136-65 mya
The Cretaceous Period was the last and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene extinction event dated at 65.5 million years ago. -
195
Jurassic 195-136 mya
Great plant-eating dinosaurs roaming the earth, feeding on lush ferns and palm-like cycads and bennettitales.smaller but vicious carnivores stalking the great herbivores. oceans full of fish, squid, and coiled ammonites, plus great ichthyosaurs and long-necked plesiosaurs. vertebrates taking to the air, like the pterosaurs and the first birds. This was the Jurassic Period, 199.6 to 145.5 million years ago. -
280
permian 280-225 mya
The Permian period lasted from 299 to 251 million years ago,and was the last period of the Paleozoic Era. The distinction between the Paleozoic and the Mesozoic is made at the end of the Permian in recognition of the largest mass extinction recorded in the history of life on Earth. It affected many groups of organisms in many different environments, but it affected marine communities the most by far, causing the extinction of most of the marine invertebrates of the time. -
500
ordovician 500-435 mya
The Ordovician Period lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago. The Ordovician is best known for its diverse marine invertebrates, including graptolites, trilobites, brachiopods, and the conodonts -
570
cambrian 570-500 mya
animals of the cambrian were developing ecological niches and strategies, such as the coralline red algae and the dasyclad green algae. -
Quaternary 1.8 Mya
Climate change and the developments it spurs carry the narrative of the Quaternary, the most recent 2.6 million years of Earth's history. Glaciers advance from the Poles and then retreat, carving and molding the land with each pulse. Sea levels fall and rise with each period of freezing and thawing. Some mammals get massive, grow furry coats, and then disappear. Humans evolve to their modern form, traipse around the globe, and make a mark on just about every Earth system, including the climate.
