Earths History

10 important events- Alyssa Knuth

Earth was created

4.5 billion years ago the Earth was created. This was caused by accretion. This was the first link to all historical events.

Great Oxidation

About 2 million years ago the great oxidation occurred. This protected life on earth from ultraviolet radiation. It also allowed the Ozone layer to form, which is a major part in Earth today.


1.25 billion years ago stromatolites appeared. Mats of bacteria reach their peak, and the amount of oxygen in the atmosphere begins to increase dramatically. This changed life on Earth dramatically.

Cambrian Explosion

This explosion caused major diversification in species. In this . In this explosion you saw an appearance of many major animal groups, including the trilobite. This also included the Burgess Shale. This happened 530 million years ago.

Soon Seas Began to Cover the Earth

This began about 500 million years ago.When seas came to the Earth many invertebrates started to populate the ocean. Many of the fish during this time were usually jawless.

Ocean Life Began

About 4 million years ago Ocean life came to the Earth. Many different organisms lived in the oceans, although they were only single celled. The picture in this slide is one that looks supposedly close to what life in the Precambrian might have looked like.

Permian Extinction

About 248 million years ago the Permian Extinction occured. This massive extinction wiped out 96% of all species that roamed among the earth.


One of the biggest events in Earths history. It formed about 245 million years ago. This was a supercontinent. It was formed after Rodinia. It contained many of the Earths continents.

The Age of Reptiles

This age was about 215 million years ago. It is also known as the Mesozoic Era. This is the age where reptiles were in control of most of the Earth. They had tons of different species.

Multi Celled Organisms

These appeared about 1 billion years ago. This made organisms more complex and various.

Works Cited

These are all of the citations for my pictures that I used for my Science project on 10 important events in Earths History.