Livyatan melvillei is an extinct species of sperm whale that lived about 9.9 to 8.9 million years ago, during the Miocene epoch. The name was inspired by the biblical sea monster Leviathan, and Herman Melville, the author of Moby-Dick. It was probably an apex predator, preying on whales and seals. The teeth, found in the Pisco Formation of Peru, measured 36.2 cm (14.3 in), the longest of any known animal, excluding tusks. The whale's length has been estimated at 13.5 to 17.5 m (44 to 57 ft), making it one of the largest predators ever. It is distinguished from the other raptorial sperm whales by the basin on the skull, and how it spans the entire length of the snout. The spermaceti organ, contained in the skull basin, is thought to have been used in echolocation and communication, or for ramming prey and other sperm whales. The whale may have competed with the giant extinct shark megalodon. Livyatan's extinction was probably caused by a cooling event at the end of the Miocene which resulted in a drop in food populations. (Full article...)