A Peruvian desert has turned out to be the final resting place of an ancient sperm whale with teeth much bigger than those of the largest of today’s sperm whales.

The fossil, dated at 12–13 million years old, belongs to a new, but extinct, genus and species described in Nature today. Named Leviathan melvillei, it probably hunted baleen whales.

A team of researchers recovered 75% of the animal’s skull, complete with large fragments of both jaws and several teeth. On the basis of its skull length of 3 metres, they estimate that Leviathan was probably 13.5–17.5 metres long, within the range of extant adult male sperm whales (Physeter macrocephalus).

Its largest teeth, however, are more than 36 centimetres long — nearly 10 centimetres longer than the largest recorded Physeter tooth.