How Did Fish Evolve?

Journey through the evolution of fish, from the first vertebrate to the fish species that would eventually evolve to crawl onto land. Biology - Animal Kingdom - Learning Points. The first fish was called Haikouichthys, and it evolved in the ocean 550 million years ago. The first fish was also the first vertebrate, and therefore the ancestor of all other vertebrates to come. Over millions of years, fish evolved tails and paired fins. Jawed fish diverged into two groups: cartilaginous fish and bony fish. In the following millions of years, the backbone evolved into a tail and eventually paired fins. It would be another 100 million years before the jaw would develop - modern-day lampreys and hagfish are relics of this primitive species. The jaw-boned species then diverged into bony fish and cartilaginous fish. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.