Frilled Shark

Photograph by Awashima Marine Park, Getty Images

Humans rarely encounter frilled sharks, which prefer to remain in the oceans' depths, up to 5,000 feet (1,500 meters) below the surface. Considered living fossils, frilled sharks bear many physical characteristics of ancestors who swam the seas in the time of the dinosaurs. This 5.3-foot (1.6-meter) specimen was found in shallow water in Japan in 2007 and transferred to a marine park. It died hours after being caught.