Geological Time Gage Harmon

Archeozoic period took place about 4 billion years ago. The atmosphere was thought to be almost lack free of oxygen. There is no sign of how life came to be but we do know but there was photosynthesis so there was oxygen molecules which implies life.

The Permian period lasted from 299 to 251 m.y.a 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.

Silurian Period was million years ago to 416 million years ago. The Silurian Period occurred from 443 million to 416 million years ago. It was the third period in the Paleozoic Era. It followed the Ordovician Period and preceded the Devonian Period.

The Paleozoic Era, which ran from about 542 million years ago to 251 million years ago, was a time of great change on Earth. The era began with the breakup of one supercontinent and the formation of another. Plants became widespread. And the first vertebrate animals colonized land.

The dinosaurs and the mammals appeared during the Triassic period, roughly 225 million years ago. The dinosaurs went extinct 65 million years ago. The Mesozoic Era lasted about 180 million years, and is divided into three periods, the Triassic, the Jurassic, and the Cretaceous.

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

The Jurassic is a geologic period and system that spans 56.3 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya.


Created with images by fortmyersfl - "#earth" • mypubliclands - "#conservationlands15 Social Media Takeover, March 15th, Prehistoric Trackways National Monument and Organ Mountains-Desert Peaks National Monument in New Mexico" • Alessio Arnese - "L'era glaciale"

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