The largest of the toothed whales, a sperm whale has the largest brain on Earth and probably dives deeper in the oceans than any other animal. This group also includes the far smaller dwarf and pygmy sperm whales.
There are several species of
sperm whales. The largest species of sperm whale has been living on Earth for around thirty million years. Pygmy sperm whales and dwarf sperm whales advanced around eight million years in the past. All three species of
sperm whales have a barrel-shaped head, a long, narrow bottom jaw with teeth, paddle-shaped flippers, and a blowhole (breathing hole) on the left side of the head. Between dives, the whales come to the surface around every eight minutes to breathe air. Two nasal passages lead from the blowhole; one is used for breathing, while the other produces sound.
