We're passionate about providing great content for our fellow shark enthusiasts! If you'd like to see more content like this you can always help us by making a donation below. Pressure form damaging human activities means that sharks are now one of the most threatened groups of animals on the planet.įind out what you can do to help by visiting our Get Involved page. Their evolution date is estimated at between 50 and 35 million years ago.ĭespite surviving 5 mass extinctions, today, many shark species are threatened with extinction. Hammerheads were the last of the modern shark families to evolve, and did so in the Cenozoic. Modern sharks and toothed whales (such as the Killer Whale) continued to flourish at the top of the food chain. THE CENOZOIC ERA (65 million years ago - present day) The end of the Mesozoic saw the fall of the great marine reptiles. This is when all modern shark families and the skates and rays first evolved. During the Jurassic period there was another rapid increase in the number of shark species. Some of the sharks from the Paleozoic period survived into the Mesozoic. THE MESOZOIC ERA (250-65 million years ago) But all modern day sharks evolved from them.
None of the sharks that lived in the Paleozoic are around today. In an age called the Carboniferous some sharks evolved weird and crazy appendages. A rapid increase in the number of shark species occurred during this time. This period saw the evolution of life from single celled organisms to bony fish and sharks. THE PALEOZOIC ERA (545-250 million years ago) It's categorised by a complete lack of animal life. This began with the evolution of the Earth 4.6 billion years ago. The entire history of our planet can be broken down into 4 stages: Yet sharks are the only group to have survived to modern day. For a brief time they were joined by other huge marine reptiles, such as Mosasaurs and Plesiosaurs. Sharks have always dominated the top of the marine food chain. Indicating that this enormous predator was as long as two buses! The massive Megalodon is an ancestor of today's infamous White Shark. One fossil tooth, belonging to a Megalodon Shark, measures a massive 17cm in length. A trait that the Megamouth Shark, Frilled Shark, Angelshark and devil rays still have today. Like many other early sharks their mouth was located at the front of their snout. One of the earliest known species was the Cladoselache. They show that some species, living over 150 million years ago, were identical to those existing today. Shark fossil records are abundant and diverse. From this, scientists can tell what the shark fed on and even identify the species it belonged to. But we can tell a lot from a single tooth. So, usually the only remains they leave behind are their teeth, dermal denticles and fin spines. After death, a shark’s skeleton rots away due to it being made of cartilage instead of bone. Yet it's likely many more existed but disappeared without trace. The fossil record documents over 3,000 shark species.
Bony fish (Osteichthyes) and cartilaginous fish (Chondrichthyes – the sharks, skates, rays and chimaera). These fish then evolved into the 2 main groups of fish seen today. It's thought that they descended from a small leaf-shaped fish that had no eyes, fins or bones. That's 200 million years before the dinosaurs! Most scientists believe that sharks came into existence around 400 million years ago.
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