Name: Livyatan melvillei
Name Meaning: Named after the biblical sea monster, Leviathan, and Herman Melville, the author of Moby-Dick; or, The Whale
Age: Miocene (12-13 million years ago)
Size: 17.5m in length approx.
Location: Peru, South America
The Pisco Formation of Southern Peru (Middle Miocene – Late Pliocene) represents a near-shore, shallow water environment from about 15 to 2 million years ago (mya). It contains a huge diversity of marine vertebrates, including bony fish, sharks, crocodiles, sea turtles, sea birds, seals and even marine sloths. But none of these were quite as awe-inspiring or terrifying as Livyatan melvillei, a sperm whale of biblical proportions. Livyatan was originally called Leviathan, but that name had already been used for a species of mastodon, so the Hebrew version was used instead.
The skull of Livyatan was roughly 3 m long and 1.9 m wide, making it the largest known fossil physteroid (the family that includes modern sperm whales). Based on the skull length, it has been estimated that Livyatan could grow up to 17.5m long, about the same size as a modern adult male sperm whale (genus Physeter). There are several key differences between Physeter and Livyatan. Whilst it had less teeth than Physeter, the teeth of Livyatan were much bigger, with a total length of more than 36.2 cm, compared to the 25 cm recorded in Physeter. Livyatan also had a much bigger temporal fossa (the area highlighted in grey on the skulls in the image below), meaning that it could accommodate a much larger musculus temporalis, the muscle which helps power the jaw.
Together, all of this means that Livyatan had an extremely dangerous bite, and was a big departure from the feeding style of Physeter, which uses a suction feeding method when preying upon creatures like squid in the deep ocean. The anatomy of Livyatan suggests a raptorial predation method, adapted for biting and gripping prey, more similar to the modern Killer Whales (genus Orcinus).
Its huge size and powerful jaws would have helped Livyatan fend off other predators that shared its waters, such as an abundance of large sharks like Carcharocles (the group which includes the infamous Megalodon) and Cosmopolitodus. Its size would help the animal keep warmer for longer periods of time, and it has been suggested that Livyatan most often preyed upon medium-sized mysticetes (baleen whales) whose high-fat content would have provided extra energy to the huge predator. All of these huge aquatic body sizes were made possible due to an increase in marine productivity in the Neogene, caused by increased weathering of new mountain ranges in North America and Asia.
It isn’t known why raptorial sperm whales like Livyatan and its kin went extinct, but this stunning animal will go down in history as one of the most terrifying yet breathtaking whales ever to prowl the oceans.
 Illustration for the exhibition “Da Leviatano a Moby Dick” (From Leviathan to Moby Dick), at the Natural History Museum of Calci. Artwork by Alberto Gennari.
 Skull, mandible and tooth of Livyatan melvillei. Teeth (e), (f) and (g) are labelled as ‘Wf’ in (d). Teeth of a modern sperm whale, Physeter (h); and a killer whale, Orcinus (i). Taken from Lambert, et al. (2010).
 The skulls of Livyatan (A), the modern sperm whale Physeter (B), and the killer whale Orcinus (C). Taken from Lambert, et al. (2010).
Information References and Further Sources
 Bianucci, G., Di Celma, C., Landini, W., Post, K., Tinelli, C., de Muizon, C., Gariboldi, K., Malinverno, E., Cantalamessa, G., Gioncada, A., Collareta, A., Gismondi, R-S., Varas-Malca, R., Urbina, M., and Lambert, O. (2016). ‘Distribution of fossil marine vertebrates in Cerro Colorado, the type locality of the giant raptorial sperm whale Livyatan melvillei (Miocene, Pisco Formation, Peru)’, Journal of Maps, 12 (3), pp. 543-557. Accessed 5th October 2020. Click Here.
 Lambert, O., Bianucci, G., Post, K., de Muizon, C., Salas-Gismondi, R., Urbina, M., and Reumer, J. (2010). ‘The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru’, Nature, 466 (7302), pp. 105-108. Accessed 5th October 2020. Click Here.
 Marx, F. G., and Uhen, M. D. (2010). ‘Climate, Critters, and Cretaceans: Cenozoic Drivers of the Evolution of Modern Whales’, Science, 327 (5968), pp. 993-996. Accessed 5th October 2020. Click Here.
 Pyenson, N. D., and Vermeij, G. J. (2016). ‘The rise of ocean giants: maximum body size in Cenozoic marine mammals as an indicator for productivity in the Pacific and Atlantic Oceans’, Biology Letters, 12 (7), p. 20160186. Accessed 5th October 2020. Click Here.