Ever wonder why sharks have so many differently shaped teeth or why they keep regrowing throughout their lives? Dr. David ...

Teeth from sharks and rays can be used to study their diet, but one of the biggest challenges in shark science is collecting ...

Their powerful jaws and elastic muscles make them formidable predators capable of inflicting severe damage. The bull shark (Carcharhinus leucas) is notorious for its aggressiveness and ...

Weirdest of all was probably Helicoprion (bottom), which had a lower jaw shaped like a buzz saw ... One species, the bull shark, can also survive in fresh water and has been found very far up ...