Cambrian Period | Universe Today

Written by Tega Jessa

The Cambrian Period is the earliest period of the Paleozoic Era and lasted from 543 million to 490 million years ago. It is considered to be one of the most important periods in Earth's history as it is believed to be the time during which more complex life forms started to first appear in an event known as the Cambrian explosion. This event is called an explosion due to the rapid diversification of life that occurred. It is believed that this produce all but one of the current major Phyla that now currently exists.

Since this period occurred so long ago we have to rely on the geological record to learn anything around. For one thing we know about the Cambrian explosion because the staggering number of fossils found. Before this there were few fossils as most organisms were either to small or simple to leave behind remains that could be fossilized.

We also know that there were the three major time divisions in this period Early Cambrian, Middle Cambrian, and Furongian. We also know through looking at the geologic record that the Cambrian period ended with a major extinction period similar to what ended the Precambrian.

Scientist also have a rough idea of the geology of the continents at the time. The supercontinent Pannotia that then existed had started to break up into 4 pieces one was Laurentia, the land mass that would become North America. The others were Baltica, the super landmass Gondwana, and what is now Siberia.

Another interesting fact is that this is one period in the geologic record when the Earth had no glaciers. This lead to a very high average sea level with most of the world's land mass covered with shallow seas. THis created the perfect environment for the explosion of diverse live that occurred. It looks like the only evidence of ice ages during this period was changes in the sea level.

In the scheme of things the Cambrian period proved to be a crucial turning point in the development of the earth. With out the emergence of diverse life that occurred during this period many of the current species that now exist would not be here and the next chapter of life on planet Earth would not occur. The fossil record left to us and other data gleaned through research also help us to have a more complete picture of the Earth throughout the ages.

If you enjoyed this article there are others on Universe Today that you will also find interesting. There is an intriguing article on whether we are living in a new geologic epoch. There is also an article on the climate of the early Earth under a younger and cooler sun.

There is also more information online. There is a great article about the Cambrian period on the National Geographic Website. There is also a great article on the University of California Berkley website.

You can also check out Astronomy Cast. Episode 96 Human to Mars talks about Terraforming.

Filed under: Astronomy