Shark facts with Zay :3

Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the division Selachii and are the sister group to the Batoidea.

Sharks have a long and fascinating history, dating back over 450 million years, making them some of the oldest vertebrates on Earth. The earliest fossil evidence for sharks or their ancestors are a few scales dating to 450 million years ago, during the Late Ordovician Period. “Shark-like scales from the Late Ordovician have been found, but no teeth. If these were from sharks it would suggest that the earliest forms could have been toothless. Scientists are still debating if these were true sharks or shark-like animals,” says Emma Bernard, a curator of fossil fish. WHICH IS REALLLYYYY PEAKK!!! It's also  thought that they descended from a small leaf-shaped fish that had no eyes, fins or bones. These fish then evolved into the 2 main groups of fish seen today. Bony fish (Osteichthyes) and cartilaginous fish (Chondrichthyes – the sharks, skates, rays and chimaera!!!!!!!!). 

The fossil record documents over 3,000 shark species. Yet it's likely many more existed but disappeared without trace. After death, a shark’s skeleton rots away due to it being made of cartilage instead of bone. So, usually the only remains they leave behind are their teeth, dermal denticles and fin spines. This is really upsetting because this means there could have been much much much much muchhhh more cool shark species we dont know about eueueueu..

BUTTTT onto fun facts, did you know that a shark can shed more than 30,000 teeth over its lifespan? Unlike humans, who have a single set of 32 permanent teeth, when a shark loses a tooth, another one will quickly take its place to ensure that these apex predators are always prepared for their next meal. If you were to peek inside a shark’s mouth, you would notice several rows of teeth behind their first row of pearly whites. So peak right.. BUT ALSO sharks never have to worry about brushing their teeth! This is because the surfaces of their teeth are coated in fluoride, keeping them safe from decay. SO UNFAIR GNG. BUT WHATS SUPER PEAK (maybe not..), SAND TIGER SHARK PUPS WILL CANNIBALIZE EACHOTHER IN THE WOMB!! THE REASON IS SO THAT THE STRONGEST SURVIVES :31!!! Also whats kinda not peak is that they don’t have vocal chords meaning they make no noises..