any of four species of beaked whales distinguished by a bulbous forehead that drops sharply to the base of the beak. All inhabit deep offshore waters and eat squid, fish, and various bottom-dwelling animals. Bottlenose whales are capable of long, deep dives; biologists recorded the dive of one northern bottlenose (Hyperoodon ampullatus) to almost 1,500 metres (4,900 feet) as it remained submerged for nearly two hours