In some form, sharks have been around for about 400 million years.
Even before dinosaurs roamed the earth, sharks hunted through the oceans! They're such good survivors that they've had little need to evolve in the last 150 million years.
These ancient predators fascinate adults and children alike.
Scientific Information: Sharks belong to the class of fish, Chondrichthyes.
Sharks have the most powerful jaws on the planet. Unlike most animals' jaws, both the sharks' upper and lower jaws move.
A shark bites with it's lower jaw first and then its upper. It tosses its head back and forth to tear loose a piece of meat which it swallows whole.
Each type of shark has a different shaped tooth depending on their diet (the shark in the photo is a great white -- you can tell he's a carnivore just by looking at those sharp, pointy teeth!).
A shark may grow and use over 20,000 teeth in its lifetime!
CARNIVORES
Almost all sharks are "carnivores" or meat eaters. They live on a diet of fish and sea mammals (like dolphins and seals) and even such prey as turtles and seagulls.
Sharks even eat other sharks. For example, a tiger shark might eat a bull shark, a bull shark might eat a blacktip shark and a blacktip shark might eat a dogfish shark!
The teeth of the carnivores are sharp and pointy. Their skeleton is made of cartilage instead of bone, which allows greater flexibility.
Their skin is made of denticles instead of ordinary fish scales. The denticles are constructed like hard, sharp teeth and help to protect the shark from injury.
Whale Sharks:
