Physeteridae

Physeteroidea is a group of whales that includes three species: the sperm whale, the pygmy sperm whale, and the dwarf sperm whale. The sperm whale is part of the genus Physeter, while the other two belong to the genus Kogia.

In the past, people sometimes classified these genera together into one family called Physeteridae, with the two Kogia species under a subgroup called Kogiinae. However, recent classifications now put the genus Kogia in its own family called Kogiidae. Meanwhile, Physeteridae is recognized as a family that only includes the single living species of sperm whale. Both families also have known fossil species.