"This is our planet...530 million years ago. Nothing yet lives on land...but in the ocean, its a different story."
The Cambrian time period was the first time period in the Palaeozoic era - the first time period when life existed on the planet. It lasted on average from 570 MYA to 490 MYA.
During the Cambrian period, nothing had yet lived on the land at this time, but under the ocean was an entirely different story. Life had already been evolving for millions of years at a slow but steady pace. The seas were mostly full of simple, soft-bodied creatures that were blindly drifting in the currents. However, in the coastal shallows below, evolution had stepped on the accelerator and predators had begun to take their first bite.
In the Cambrian, the ability to see and react to enemies triggered an arms race between predatory and prey. This battle even continues today and is a major force behind the variety of life. To combat being visible and vulnerable, around 80% of creatures in the Cambrian seas had sturdy skeletons on the outside of their bodies. These armored animals are called Arthropods. Upon their extinction, they gave rise to incests and arachnids. However, in the crowded waters of the Cambrian, there was competition everywhere.
The list of animals during the Cambrian: