History of B.C.
The Cambrian Explosion
For most of its prehistoric life, British Columbia was under water. This is why most of British Columbia's fossils are ocean and marine creatures. In the Cambrian period British Columbia was part of what was known as Laurentia, a continent made up of Honduras, Mexico, Canada, the United States, and Greenland. Laurentia, which was situated on the Equator, was quite small compared to Gondwana (made up of present-day Africa and South America), and most of it was underwater. The seas were filled with small, unusually diverse, soft-bodied marine creatures. Such creatures included primitive arthropods, jellyfish, echinoderms, sponges, and trilobites. Early in the Cambrian, sea creatures developed hard parts for protection and support for their soft bodies. Animals with a skeleton grew larger, and began to live in different areas on the sea floor. Others evolved to swim faster, and developed into predators. By the end of the Cambrian, the ancestors of most major animal groups had developed in the ocean.
A mass extinction occurred at the end of the Cambrian, wiping out large numbers of the diverse creatures that had evolved in this period, possibly because of the cooling of the seas, and the lack of oxygen in the water.
In the Ordovician period, British Columbia, still part of Laurentia, rotated counter clockwise and moved closer to Gondwana. The continents were all situated along the equator or to the south of it. More of Laurentia became flooded and there were large, shallow seas with clear and warm water. This provided a good environment for algae growth, which in turn was food for a thriving animal life. Some creatures that existed during this period were straight and coiled nautiloids (squid), trilobites, cup corals, early sea urchins, lamp shells, and early snails.