Livyatan is an extinct genus of macroraptorial sperm whale, containing one known species: L. melvillei. The genus name was inspired by the biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous novel Moby-Dick about a white bull sperm whale. Herman Melville often referred to whales as "Leviathans" in his book. It is mainly known from the Pisco Formation of Peru during the Tortonian stage of the Miocene epoch, about 8.9–9.9 million years ago (mya); however, finds of isolated teeth from other locations such as Chile, Argentina, the United States (California), South Africa and Australia imply that either it or a close relative survived into the Pliocene, around 5mya, and may have had a global presence.
The body length of Livyatan melvillei holotype is approximately long. Comparable to that of the modern sperm whale (Physeter macrocephalus), making it one of the largest predators known. The teeth of Livyatan measured and are the largest biting teeth of any known animal, excluding tusks. It is distinguished from the other raptorial sperm whales by the basin on the skull spanning the length of the snout. The spermaceti organ contained in that basin is thought to have been used in echolocation and communication, or for ramming prey and other sperm whales. The whale may have interacted with the large extinct shark megalodon (Otodus megalodon), competing with it for a similar food source. Its extinction was probably caused by a cooling event at the end of the Miocene period causing a reduction in food populations. The geological formation where the whale has been found has also preserved a large assemblage of marine life, such as sharks and other marine mammals. Characteristically of raptorial sperm whales, Livyatan had functional, enamel-coated teeth on the upper and lower jaws, as well as several features suitable for hunting large prey.
Research history Holotype and naming
In November 2008, a partially preserved skull with the teeth and lower jaw, the holotype specimen (MUSM 1676) of Livyatan melvillei, was discovered in the coastal desert of Peru in the sediments of the Pisco Formation, southwest of the city of Ica. Klaas Post, a researcher for the Natural History Museum Rotterdam in the Netherlands, stumbled across them on the final day of a field trip. The fossils were prepared in Lima, and are now part of the collection of the Museum of Natural History, Lima of National University of San Marcos.
The discoverers originally assigned the English name of the biblical monster, Leviathan, to the whale as Leviathan melvillei. However, the scientific name Leviathan was preoccupied by Leviathan Koch, 1841, a junior synonym for the mastodon (Mammut). In August 2010, the authors rectified this situation by coining a new genus name for the whale, Livyatan, from the original Hebrew name of the monster. The species name melvillei is a reference to Herman Melville, author of the book Moby-Dick, which features a gigantic sperm whale as the main antagonist. The first Livyatan fossils from Peru were initially dated to around 13–12 million years ago (mya) in the Serravallian Age of the Miocene, but this was revised to 9.9–8.9 mya in the Tortonian Age of the Miocene.
Additional specimens
During the late 2010s and into the 2020s, fossils of large isolated sperm whale teeth were reported from various Miocene and Pliocene localities, mostly from the Southern Hemisphere. These teeth have been identified as similar in size and shape to those of the L. melvillei holotype and may represent species of Livyatan. However, it is commonplace that authors do not identify such teeth as a conclusive species of Livyatan, instead opting to assign an open nomenclature in which the biological classifications of the specimens are restricted to comparisons or affinities with Livyatan. This is mostly because isolated teeth tend to not be informative enough to be identified at the species level, meaning that there is some undeterminable possibility that they belong to an undescribed close relative of Livyatan rather than Livyatan itself.
In 2016, in Beaumaris Bay, Australia, a large sperm whale tooth measuring , specimen NMV P16205, was discovered in Pliocene strata by a local named Murray Orr, and was nicknamed the "Beaumaris sperm whale" or the "giant sperm whale". The tooth was donated to Museums Victoria at Melbourne. Though it has not been given a species designation, the tooth looks similar to those of L. melvillei, indicating it was a close relative. The tooth is dated to around 5mya, and so is younger than the L. melvillei holotype by around 4or 5million years.
In 2018, palaeontologists led by David Sebastian Piazza, while revising the collections of the Bariloche Paleontological Museum and the Municipal Paleontological Museum of Lamarque, uncovered two incomplete sperm whale teeth cataloged as MML 882 and BAR-2601 that were recovered from the Saladar Member of the Gran Bajo del Gualicho Formation in the Río Negro Province of Argentina, a deposit that dates between around 20–14 mya. The partial teeth measure and in height, respectively. Anatomical analyses of the specimens found that many of their characteristics are identical to L. melvillei except in width, in which the diameter of both teeth are smaller. Because of this, along with only isolated teeth being available, the palaeontologists chose to assign an open nomenclature, identifying both specimens as aff. Livyatan sp.
In 2019, palaeontologist Romala Govender reported the discovery of two large sperm whale teeth from Pliocene deposits near the Hondeklip Bay village of Namaqualand in South Africa. The pair of teeth, which are stored in the Iziko South African Museum and cataloged as SAM-PQHB-433 and SAM-PQHB-1519, measure and in height, respectively, the latter having its crown missing. Both teeth have open pulp cavities, indicating that both whales were young. The teeth are very similar in shape and size to the mandibular teeth of the L. melvillei holotype, and were identified as cf. Livyatan. Like the Beaumaris specimen, the South African teeth are dated to around 5mya.
In 2025, Kristin Watmore and Donald Prothero reported a giant sperm whale tooth identified as cf. Livaytan discovered in Mission Viejo, California, during housing development during the 1980s and '90s. The tooth resided in the Orange County Paleontological Collection, cataloged as OCPC 3125/66099, and was incomplete but nevertheless measured at least in length and in diameter. Due to poor geographic recording at the time of its discovery, the exact stratigraphic locality was unknown, but it was reported to have come from a zone that contains both the mid-Miocene Monterey Formation and younger Capistrano Formation, the latter dating between 6.6 and 5.8 mya. The authors found the preservation of the tooth to be more consistent with Capistrano Formation fossils. The broken tooth surface exposed layers of cementum and dentin whose thicknesses fall within the known range of L. melvillei teeth. OCPC 3125/66099 represented the first evidence that either Livyatan or Livyatan-like whales were not restricted to the Southern Hemisphere and likely indicated a possibly global distribution of the cetaceans.
Description
The body length of Livyatan melvillei is estimated around mainly based on the holotype skull due to the lack of postcranial remains. Lambert and colleagues estimated the body length of Livyatan by comparing it to other physeteroids, Zygophyseter and modern sperm whales. The authors opted to use the relationship between the bizygomatic width (distance between the opposite zygomatic processes) of the skull and body length because of the variable rostrum length in modern sperm whales and the rostrum of Livyatan being proportionally shorter. This approach yielded length estimates of using modern sperm whales and using Zygophyseter, with the latter range caused by the incompleteness of the Zygophyseter type specimen. It has been estimated to weigh based on the length estimate of . A 2025 study estimated the body length of Livyatan Holotype approximately between and with the former potentially being an underestimation as the equations used for those estimates may underestimate total body lengthSupplementary Data Table S1. By comparison, the modern sperm whale length measures on average for females and for males, with some males reaching up to . The large size was probably an anti-predator adaptation, and allowed it to feed on larger prey. Livyatan is the largest extinct physeteroid discovered, possibly having one of the strongest bite forces of any tetrapod.
Skull The holotype skull of Livyatan was about long. Like other raptorial sperm whales, Livyatan had a wide gap in between the temporal fossae on the sides of the skull and the zygomatic processes on the front of the skull, indicating a large space for holding strong temporal muscles, which are the most powerful muscles between the skull and the jaw. The snout was robust, thick, and relatively short, which allowed it to clamp down harder and better handle struggling prey. The left and right premaxillae on the snout probably did not intersect at the tip of the snout, though the premaxillae took up most of the front end of the snout. Unlike in the modern sperm whale, the premaxillae reached the sides of the snout. The upper jaw was thick, especially midway through the snout. The snout was asymmetrical, with the right maxilla in the upper jaw becoming slightly convex towards the back of the snout, and the left maxilla becoming slightly concave towards the back of the snout. The vomer reached the tip of the snout and was slightly concave, decreasing in thickness from the back to the front. A sudden thickening in the middle-left side of the vomer may indicate the location of the nose plug muscles. Each mandible in the lower jaw was higher than it was wide, with a larger gap in between the two than in the modern sperm whale. The mandibular symphysis, which connects the two halves of the mandibles in the middle of the lower jaw, was unfused. The condyloid process, which connects the lower jaw to the skull, was located near the bottom of the mandible, like other sperm whales. The head probably took up 17–22% of the total body size, compared to that of the modern sperm whale which takes up around one fourth to one third of the total body size. Like in other sperm whales, the blowhole was slanted towards the left side of the animal, and it may have lacked a right nasal passage.
A 2022 study which examined specimens of multiple phseteroids, including the holotype skull of Livyatan discovered bite marks consistent with the teeth of either the modern Great White Shark (Carcharodon carcharias) or the extinct Otodus megalodon, these bite marks came from a region of the skull which would have only been accessible to scavengers.
Teeth
Unlike the modern sperm whale, Livyatan had functional teeth in both jaws. The wear on the teeth indicates that the teeth sheared past each other while biting down, meaning it could bite off large portions of flesh from its prey. Also, the teeth were deeply embedded into the gums and could interlock, which were adaptations to holding struggling prey. None of the teeth of the holotype were complete, and none of the back teeth were well-preserved. The lower jaw contained 22 teeth, and the upper jaw contained 18 teeth. Unlike other sperm whales with functional teeth in the upper jaw, none of the tooth roots were entirely present in the premaxilla portion of the snout, being at least partially in the maxilla. Consequently, its tooth count was lower than those sperm whales, and, aside from the modern dwarf (Kogia sima) and pygmy (K. breviceps) sperm whales, it had the lowest tooth count in the lower jaw of any sperm whale.