This explains the lack of fossilized shark bones in existence. There are more than 350 species of sharks worldwide, and 400 species of rays. Most sharks are cold-blooded. Their inner body temperature matches the water temperature. Sharks don't blink.
Some sharks can live for a year without eating.
Contents found in the stomachs of tiger sharks include lobsters, stingrays, sea turtles, porpoises, human limbs, dogs, tin cans, garbage, coal and a full suit of armor. Hammerhead sharks are born with their heads bent backwards so they don't get stuck in the birth canal.