The Cambrian Explosion

Exhibit by Patricia Brennan

The Cambrian Explosion refers to a sharp and sudden increase in the rate of evolution.

About 543 million years ago, in the early Cambrian period, intense diversification resulted in more than 35 new animal phyla. However, new discoveries show that the "explosion" started ~565 Ma in the Neoproterozic era.

Geologists and paleontologists studying Neoproterozoic and Cambrian aged rocks, molecular biologists' advances understanding genetic relationships between animal phylum, are bringing in new evidence and new interpretations at such a rate that the story changes and becomes clearer almost on a monthly basis.
Painting by Mike Leveille, photographed by Sonia Boucher

Hints for Navigating the Exhibit

When you are in a section of the exhibit, click on the left-facing Marella to return to the previous page. Click on the globe to return home to the Exhibit Guide. To go to the next page, click on the right-facing Marella.

You can click on text written in blue to go to a page on that topic. For example, click on the word "Marella" to see more about this animal.

Click on time references in blue to go to a geologic time chart. Try clicking on "543 million years ago" to see the time chart.

To return to the page you came from, use the "back" button on the top right of the tool bar.

Remember, clicking on the image of the globe will take you to the home page of the exhibit.