Precambrian Time
Lets begin with the first, and in some ways most important period of time. Earth formed 4.6 Billion Years Ago(BYA) the earth started out as a ball of dust once the earth was fully formed, the Precambrian Time period started. When earth was warm, algae started to invade the oceans in clumps. When earth got extremely cold Glaciers started to form near the equator! Most of the time it was warm then cold,warm and cold for about 100,000 years at a time. The climate followed the continents in their drifting stages. When earth first began there was a huge landform/supercontinent,this supercontinent was called “Pangea”. On Pangea a bunch of volcanoes formed and then the continents started to drift slowly. 4.6 Billion Years(BY) later the continents are how they are now.(It took 4.6 Billion years!)
Although there was no real animal life there was Single and Multi-celled animals. One of the first creatures on the earth was the Jellyfish,the Jellyfish had a mouth but no backside(rump). The next animal is classified today as a microfossil this organism was called the Acritarch. The Acritarch was also a micro-plankton. Autotrophs were soft-bodied heterotrophs (Heterotrophs feed and get energy of of other single-celled organisms). Although most plants were not identified, when the first plants started to evolve because of photosynthesis. When the first plants started to evolve, animals started to appear because of the sudden increase in oxygen. At the end of the era There was a major drop in oxygen and that caused: a mass extinction, the Ozone layer formed, The sea level dropped and single celled algae disappeared.This era ended 543 MYA.
Although there was no real animal life there was Single and Multi-celled animals. One of the first creatures on the earth was the Jellyfish,the Jellyfish had a mouth but no backside(rump). The next animal is classified today as a microfossil this organism was called the Acritarch. The Acritarch was also a micro-plankton. Autotrophs were soft-bodied heterotrophs (Heterotrophs feed and get energy of of other single-celled organisms). Although most plants were not identified, when the first plants started to evolve because of photosynthesis. When the first plants started to evolve, animals started to appear because of the sudden increase in oxygen. At the end of the era There was a major drop in oxygen and that caused: a mass extinction, the Ozone layer formed, The sea level dropped and single celled algae disappeared.This era ended 543 MYA.