After the Earth had turned from a sterile ball of gas into a fertile, aquiferous planet (with the help of crashing meteorites and a collision with the planet Thea), the Cambrian period started. During this time, life on Earth had exploded, and millions of organisms had transformed from the simple, single-celled organisms that they were in the Precambrian into the complex, multi-celled organisms that would rule Earth for the rest of time. While the land was uninhabited (and uninhabitable), the oceans were filled with a diverse collection of life. The main rulers of the waters were the arthropods; the most prominent arthropods were the trilobites (which were a diverse class of animals that would flourish in the oceans for the rest of the Paleozoic) and the radiodonts (which were the apex predators of the time). However, they were not alone, as they shared these waters with the fish (which started out small, and would remain small for 2 more periods) and the mollusks. As well as this, many echinoderms, corals, and aquatic plants evolved. Soon, the warm temperatures that were present in this beautiful period would drop, driving many genera to extinction and giving rise to the Ordovician.
Lasted from 541-485.4 mya
Terrenuevian Animals (note that those are not all the ones that exist)Edit
Series 2 Animals (note that those are not all the ones that exist)Edit
Series 3 Animals (note that those are not all the ones that exist)Edit
Furongian Animals (note that those are not all the ones that exist)Edit