Mysteries surround the elusive Greenland shark, the longest-living vertebrate in the world. Researchers have new insight into the unique fish’s genetic makeup.

But the great white is only one member of the diverse shark family. More than 400 kinds of sharks swim the world’s oceans. Here are four other species: An odd-looking and rarely seen shark lurks ...

The first sharks on Earth: Ancient relatives of sharks first appeared in the world's oceans about 400 million years ago ... Number of species: There are well over 350 known species of sharks ...