Life in the Precambrian Era
The Precambrian Era began about 4570 million years ago. The time period began due to the Earth's formation. The Archean period was the first period too occur during this era. Earth, during this time period, was very rocky and mountainous with volcanos and lava as well.
Life first appeared when Earth was about 600 million years old. The lava from the inside of Earth had cooled down, and oceans began to form. The earliest type of living creatures were microscopic bacteria. At the end of the Precambrian Era, hard-shelled animals and multicellular organisms were inhabiting Earth before the ice age occurred. The environment where living things were, was very dry, but over time the certain plants and animal organisms had formed slight mat-like areas that covered terrestrial areas.
The Precambrian Era ended about 541 million years ago. It is believed by scientists that a giant ice age had occurred which had caused the end of the era. The ice age was believed to kill off some of the organisms that had been alive. Other organisms had been preserved in ice. Approximately 30% of Earth was covered in ice during the ice age.
Life first appeared when Earth was about 600 million years old. The lava from the inside of Earth had cooled down, and oceans began to form. The earliest type of living creatures were microscopic bacteria. At the end of the Precambrian Era, hard-shelled animals and multicellular organisms were inhabiting Earth before the ice age occurred. The environment where living things were, was very dry, but over time the certain plants and animal organisms had formed slight mat-like areas that covered terrestrial areas.
The Precambrian Era ended about 541 million years ago. It is believed by scientists that a giant ice age had occurred which had caused the end of the era. The ice age was believed to kill off some of the organisms that had been alive. Other organisms had been preserved in ice. Approximately 30% of Earth was covered in ice during the ice age.
Works Cited
"Precambrian Era." Precambrian Era. N.p., n.d. Web. 21 Mar. 2013. <http://www.geo.msu.edu/geogmich/Precambrian.html>
"Precambrian Time." National Geographic. N.p., n.d. Web. 21 Mar. 2013. <http://science.nationalgeographic.com/science/prehistoric-world/precambrian/>
"Precambrian Era." Precambrian Era. N.p., n.d. Web. 21 Mar. 2013. <http://www.geo.msu.edu/geogmich/Precambrian.html>
"Precambrian Time." National Geographic. N.p., n.d. Web. 21 Mar. 2013. <http://science.nationalgeographic.com/science/prehistoric-world/precambrian/>