The sperm whale superfamily, called Physteroidea, includes only 3 living species; the sperm whale, the dwarf sperm whale and the pygmy sperm whale. Sperm whales are in a different genus than their smaller counterparts, but all three species share some similar features that are unique to this superfamily. All members of this group have relatively small and thin, under-slung lower jaws and simple teeth. Teeth may not erupt or may even be absent from the upper jaw. They have asymmetrical nasal bones, with a single blowhole on the top left of their heads. They also have a spermaceti organ; an organ unique to this group that is filled with a waxy, semi-liquid white substance called spermaceti which may serve as ballast for diving and aid in buoyancy control....
Newsletter
Sign up for our monthly e-newsletter: