Sharks, skates, rays and chimaeras stand apart from other jawed vertebrates in having a skeleton that is made primarily of cartilage rather than bone.
Sharks are classified as vertebrates, meaning they have a backbone. A shark's backbone is not really made out of bone it is cartilage. Scientists consider sharks fish.
Sharks do not have bones. They are a special type of fish known as "elasmobranchs", which translates into fish made of cartilaginous tissues—the clear gristly stuff that your ears and nose tip are made of.
Different parts of a shark's skeleton can have very different types of cartilage with different structure and function. But the whole skeleton, including the jaws, is made of cartilage. Well, like our teeth, shark teeth are made of a tissue called dentin (“dentine” for our British readers), which is calcified.
Later, after Caroline's health had improved, Caroline was smothered to death in the hospital by Katherine Pierce, who was aware that Damon had healed Caroline, therefore knowingly turned her into a vampire.
"Black Hole Sun" is the 4th episode of the sixth season of the American series The Vampire Diaries and the series' 115th episode overall.