''Livyatan'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of macroraptorial

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genus ''Physeter'' and one of three extant species in the s ...

containing one known species: ''L. melvillei''. The genus name was inspired by the

biblical The Bible is a collection of religious texts that are central to Christianity and Judaism, and esteemed in other Abrahamic religions such as Islam. The Bible is an anthology (a compilation of texts of a variety of forms) biblical languages ...

sea monster

Leviathan Leviathan ( ; ; ) is a sea serpent demon noted in theology and mythology. It is referenced in several books of the Hebrew Bible, including Psalms, the Book of Job, the Book of Isaiah, and the pseudepigraphical Book of Enoch. Leviathan is of ...

, and the species name by

Herman Melville Herman Melville (Name change, born Melvill; August 1, 1819 – September 28, 1891) was an American novelist, short story writer, and poet of the American Renaissance (literature), American Renaissance period. Among his best-known works ar ...

, the author of the famous novel ''

Moby-Dick ''Moby-Dick; or, The Whale'' is an 1851 Epic (genre), epic novel by American writer Herman Melville. The book is centered on the sailor Ishmael (Moby-Dick), Ishmael's narrative of the maniacal quest of Captain Ahab, Ahab, captain of the whaler ...

'' 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 The Pisco Formation is a geologic formation located in Peru, on the southern coastal desert of Ica, Peru, Ica and Arequipa. The approximately thick formation was deposited in the Pisco Basin, spanning an age from the Miocene, Late Miocene up to t ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

during the

Tortonian The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Tort ...

stage of the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

, about 9.9–8.9 million

year A year is a unit of time based on how long it takes the Earth to orbit the Sun. In scientific use, the tropical year (approximately 365 Synodic day, solar days, 5 hours, 48 minutes, 45 seconds) and the sidereal year (about 20 minutes longer) ...

s ago (mya); however, finds of isolated teeth from other locations such as

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

, the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

(

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

imply that either it or a close relative survived into the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58macroraptorial sperm whale Macroraptorial sperm whales were highly predatory whales of the sperm whale superfamily (Physeteroidea) of the Miocene epoch (geology), epoch that hunted large marine mammals, including other whales, using their large teeth. They consist of six ge ...

s (or "raptorial sperm whales") and was probably an

apex predator An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hig ...

, preying on whales, seals and so forth. 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. ''Livyatan''s total length has been estimated to be about , almost similar to that of the modern

(''Physeter macrocephalus''), making it one of the largest predators known to have existed. 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 A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, Rostrum (anatomy), rostrum, beak or proboscis. The wet furless surface around the nostrils of the n ...

. The

spermaceti organ The spermaceti organ is an organ present in the heads of toothed whales of the superfamily Physeteroidea, in particular the sperm whale. The organ contains a waxy liquid called spermaceti and is thought to be involved in the generation of sound ...

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'' ( ; meaning "big tooth"), Common name, commonly known as megalodon, is an extinction, extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Earl ...

(''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

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s and other

marine mammal Marine mammals are mammals that rely on marine ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine enviro ...

Research history

Holotype and naming

In November 2008, a partially preserved skull, as well as teeth and the lower jaw, belonging to ''L.'', the

holotype specimen A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was Species description, formally described. It is either the single such physical example (or illus ...

MUSM 1676, were discovered in the coastal desert of Peru in the sediments of the

, southwest of the city of Ica. Klaas Post, a researcher for the

Natural History Museum Rotterdam The (; ) is a natural history museum located in Rotterdam, Netherlands. The museum opened in 1927. It had 44,009 visitors in 2015. History In 1922, the Rotterdam section of the Nederlandsche Natuurhistorische Vereeniging (Dutch Natural Hist ...

in the Netherlands, stumbled across them on the final day of a field trip. The fossils were prepared in

Lima Lima ( ; ), founded in 1535 as the Ciudad de los Reyes (, Spanish for "City of Biblical Magi, Kings"), is the capital and largest city of Peru. It is located in the valleys of the Chillón River, Chillón, Rímac River, Rímac and Lurín Rive ...

, and are now part of the collection of the Museum of Natural History, Lima of

National University of San Marcos The National University of San Marcos (, UNMSM) is a public university, public research university located in Lima, the capital of Peru. In the Americas, it is the first officially established (Privilege (legal ethics), privilege by Charles V, ...

. The discoverers originally assigned—in July 2010—the English name of the biblical monster, Leviathan, to the whale as ''Leviathan melvillei''. However, the scientific name ''Leviathan'' was also the

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

for the

mastodon A mastodon, from Ancient Greek μαστός (''mastós''), meaning "breast", and ὀδούς (''odoús'') "tooth", is a member of the genus ''Mammut'' (German for 'mammoth'), which was endemic to North America and lived from the late Miocene to ...

(''Mammut''), so, in August 2010, the authors rectified this situation by coining a new genus name for the whale, ''Livyatan'', from the original

Hebrew Hebrew (; ''ʿÎbrit'') is a Northwest Semitic languages, Northwest Semitic language within the Afroasiatic languages, Afroasiatic language family. A regional dialect of the Canaanite languages, it was natively spoken by the Israelites and ...

name of the monster. The

species name In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...

''melvillei'' is a reference to

, author of the book ''

'', which features a gigantic sperm whale as the main

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain. The first ''Livyatan'' fossils from Peru were initially dated to around 13–12 million years ago (mya) in the

Serravallian The Serravallian is, in the geologic timescale, an List of time periods, age or a stage (stratigraphy), stage in the middle Miocene epoch (geology), Epoch/series (stratigraphy), Series, which spans the time between 13.82 annum, Ma and 11.63 Ma (m ...

Age of the Miocene, but this was revised to 9.9–8.9 mya in the

Age of the Miocene.

Additional specimens

During the late 2010s and 2020s, fossils of large isolated sperm whale teeth were reported from various Miocene and Pliocene localities mostly along the Southern Hemisphere. These teeth have been identified to be of similar size and shape with that of the ''L. melvillei'' holotype and may be 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 Open nomenclature is a vocabulary of partly informal terms and signs in which a taxonomist may express remarks about their own material. This is in contrast to synonymy lists, in which a taxonomist may express remarks on the work of others. Common ...

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 Beaumaris Bay ( ) is a short but wide bay within the eastern shore of Port Phillip Bay in southern Victoria, Australia. It commences at the cliffs of Rickett's Point in the southern end of the Melbourne suburb of Beaumaris, then recesses north b ...

, Australia, a large sperm whale tooth measuring , specimen NMV P16205, was discovered in Pliocene

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

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 Museums Victoria is an organisation that includes a number of museums and related bodies in Melbourne. These include Melbourne Museum, Immigration Museum, Scienceworks, IMAX Melbourne, a research institute, the UNESCO World Heritage-listed Roy ...

Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...

. 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

, a deposit that dates between around 20–14 mya. The partial teeth measure and in height, respectively. Anatomical analyses of the specimens found that much 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 Namaqualand ( Khoikhoi: "Nama-kwa" meaning Nama Khoi people's land) is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of . It is divided by the lower course of the Orange River int ...

. The pair of teeth, which are stored in the

Iziko South African Museum The Iziko South African Museum, formerly the South African Museum (Afrikaans: Suid-Afrikaanse Museum), is a South African national museum located in Cape Town. The museum was founded in 1825, the first in the country. It has been on its present ...

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 2023, graduate student Kristin Watmore and paleontologist

Donald Prothero Donald Ross Prothero (February 21, 1954) is an American geologist, paleontologist, and author who specializes in mammalian paleontology and magnetostratigraphy, a technique to date rock layers of the Cenozoic era and its use to date the climate ...

reported in a preprint a giant sperm whale tooth identified as ''cf. Livaytan'' discovered in

Mission Viejo, California Mission Viejo ( ; language change, corruption of ; ) is a Commuter town, commuter city in the Saddleback Valley in Orange County, California, United States. Mission Viejo is considered one of the largest Planned community, master-planned commu ...

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 Zone, Zones or The Zone may refer to: Places Military zones * Zone, any of the divisions of France during the World War II German occupation * Zone, any of the divisions of Germany during the post-World War II Allied occupation * Korean Demilit ...

that contains both the mid-Miocene

Monterey Formation The Monterey Formation is an extensive Miocene oil-rich geology, geological sedimentary formation in California, with outcrops of the formation in parts of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shor ...

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. At the area where part of the tooth broke off revealed layers of

cementum Cementum is a specialized calcified substance covering the root of a tooth. The cementum is the part of the periodontium that attaches the teeth to the alveolar bone by anchoring the periodontal ligament. Structure The cells of cementum are ...

and

dentin Dentin ( ) (American English) or dentine ( or ) (British English) () is a calcified tissue (biology), tissue of the body and, along with tooth enamel, enamel, cementum, and pulp (tooth), pulp, is one of the four major components of teeth. It i ...

of thickness 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'' is unknown since only the holotype skull is preserved. Lambert and colleagues estimated the body length of ''Livyatan'' using ''Zygophyseter'' and modern

s as a guide''.'' The authors opted to use the relationship between the bizygomatic width (distance between the opposite

zygomatic process The zygomatic processes (aka. malar) are three processes (protrusions) from other bones of the skull which each articulate with the zygomatic bone. The three processes are: * Zygomatic process of frontal bone from the frontal bone * Zygomatic ...

es) of the skull and body length because of the variable

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

length in modern sperm whales and the rostrum of ''Livyatan'' being proportionally shorter. Doing so produced length estimates of when using the modern sperm whale and when using ''Zygophyseter.'' It has been estimated to weigh based on the length estimate of . By comparison, the modern sperm whale length measures on average for females and for males, with some males reaching up to long. The large size was probably an

anti-predator adaptation Anti-predator adaptations are mechanisms developed through evolution that assist Predation, prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, na ...

, and allowed it to feed on larger prey. ''Livyatan'' is the largest fossil sperm whale discovered, and was also one of the biggest-known predators, having the largest bite of any

tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

Skull

The holotype skull of ''Livyatan'' was about long. Like other raptorial sperm whales, ''Livyatan'' had a wide gap in between the

temporal fossa The temporal fossa is a fossa (shallow depression) on the side of the skull bounded by the temporal lines above, and the zygomatic arch below. Its floor is formed by the outer surfaces of four bones of the skull. The fossa is filled by the te ...

e on the sides of the skull and the zygomatic processes on the front of the skull, indicating a large space for holding strong

temporal muscle In anatomy, the temporalis muscle, also known as the temporal muscle, is one of the muscles of mastication (chewing). It is a broad, fan-shaped convergent muscle on each side of the head that fills the temporal fossa, superior to the zygomatic ...

s, which are the most powerful muscles between the skull and the jaw. The

was robust, thick and relatively short, which allowed it to clamp down harder and better handle struggling prey. The left and right

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...

e 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 vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

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 The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

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 jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

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 In human anatomy, the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge, indicating the mandibular symphysis (Latin: ''symphysis menti'') or line of junction where the two lateral ha ...

which connects the two halves of the mandibles in the middle of the lower jaw was unfused. The

condyloid process The condyloid process or condylar process is the process on the human and other mammalian species' mandibles that ends in a condyle, the mandibular condyle. It is thicker than the coronoid process of the mandible and consists of two portions: the ...

, which connects the lower jaw to the skull, was located near the bottom of the mandible like other sperm whales.

Teeth

Unlike the modern sperm whale, ''Livyatan'' had functional teeth in both jaws. The wearing 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

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 Dwarf, dwarfs or dwarves may refer to: Common uses *Dwarf (folklore), a supernatural being from Germanic folklore * Dwarf, a human or animal with dwarfism Arts, entertainment, and media Fictional entities * Dwarf (''Dungeons & Dragons''), a sh ...

(''Kogia sima'') and

pygmy In anthropology, pygmy peoples are ethnic groups whose average height is unusually short. The term pygmyism is used to describe the phenotype of endemic short stature (as opposed to disproportionate dwarfism occurring in isolated cases in a po ...

(''K. breviceps'') sperm whales, it had the lowest tooth count in the lower jaw of any sperm whale. The most robust teeth in ''Livyatan'' were the fourth, fifth and sixth teeth in each side of the jaw. The well-preserved teeth all had a height greater than , and the largest teeth of the holotype were the second and third on the left lower jaw, which were calculated to be around high. The first right tooth was the smallest at around . The Beaumaris sperm whale tooth measured around in length, and is the largest fossil tooth discovered in Australia. These teeth are thought to be among the largest of any known animal, excluding

tusk Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine tooth, canine teeth, as with Narwhal, narwhals, chevrotains, musk deer, water deer, muntjac, pigs, ...

s. Some of the lower teeth have been shown to contain a facet for when the jaws close, which may have been used to properly fit the largest teeth inside the jaw. In the front teeth, the tooth diameter decreased towards the base. This was the opposite for the back teeth, and the biggest diameters for these teeth were around in the lower jaw. All teeth featured a rapid shortening of the diameter towards the tip of the tooth, which were probably in part due to wearing throughout their lifetimes. The curvature of the teeth decreased from front to back, and the lower teeth were more curved at the tips than the upper teeth. The front teeth projected forward at a 45° angle, and, as in other sperm whales, cementum was probably added onto the teeth throughout the animal's lifetime. Livyatan skull

All tooth sockets were cylindrical and single-rooted. The tooth sockets increased in size from the first to the fourth and then decreased, the fourth being the largest at around in diameter in the upper jaws, which is the largest of any known whale species. The tooth sockets were smaller in the lower jaw than they were in the upper jaw, and they were circular in shape, except for the front sockets which were more ovular.

Basin

The fossil skull of ''Livyatan'' had a curved basin, known as the supracranial basin, which was deep and wide. Unlike other raptorial sperm whales, but much like in the modern sperm whale, the basin spanned the entire length of the snout, causing the entire skull to be concave on the top rather than creating a snout as seen in ''

Zygophyseter ''Zygophyseter varolai'' is an extinct sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genu ...

'' and '' Acrophyseter''. The supracranial basin was the deepest and widest over the

braincase In human anatomy, the neurocranium, also known as the braincase, brainpan, brain-pan, or brainbox, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calv ...

, and, unlike other raptorial sperm whales, it did not overhang the

eye socket In anatomy, the orbit is the cavity or socket/hole of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is ...

. It was defined by high walls on the sides. The antorbital notches, which are usually slit-like notches on the sides of the skull right before the snout, were inside the basin. A slanting crest on the temporal fossa directed towards the back of the skull separated the snout from the rest of the skull, and was defined by a groove starting at the antorbital processes on the cheekbones. The basin had two

foramina In anatomy and osteology, a foramen (; : foramina, or foramens ; ) is an opening or enclosed gap within the dense connective tissue (bones and deep fasciae) of extant and extinct amniote animals, typically to allow passage of nerves, arter ...

in the front, as opposed to the modern sperm whale which has one foramen on the maxilla, and to the modern dwarf and pygmy sperm whales which have several in the basin. The suture in the basin between the maxilla and the

forehead In human anatomy, the forehead is an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows. The bottom of the fo ...

had an interlocking pattern.

Classification

''Livyatan'' was part of a fossil

stem group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

of hyper-predatory

sperm whales The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus '' Physeter'' and one of three extant species in the sperm whale super ...

commonly known as

macroraptorial sperm whale Macroraptorial sperm whales were highly predatory whales of the sperm whale superfamily (Physeteroidea) of the Miocene epoch (geology), epoch that hunted large marine mammals, including other whales, using their large teeth. They consist of six ge ...

s, or raptorial sperm whales, alongside the extinct whales ''

Brygmophyseter ''Brygmophyseter'', known as the biting sperm whale, is an extinct genus of toothed whale in the Physeteroidea, sperm whale family with one species, ''B. shigensis''. When it was first described in 1994, the species was placed in the genus ''Sc ...

'', '' Acrophyseter'' and ''

''. This group is known for having large, functional teeth in both the upper and lower jaws, which were used in capturing large prey, and had an enamel coating. Conversely, the modern

(''Physeter macrocephalus'') lacks teeth in the upper jaw, and the ability to use its teeth to catch prey. ''Livyatan'' belongs to a different lineage in respect to the other raptorial sperm whales, and the size increase and the development of the

, an organ that is characteristic of sperm whales, are thought to have evolved independently from other raptorial sperm whales. The large teeth of the raptorial sperm whales either evolved once in the group with a basilosaurid-like common ancestor, or independently in ''Livyatan''. The large

in the skull of raptorial sperm whales is thought to a

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, an ...

feature, that is, a trait inherited from a common ancestor. Since the teeth of

foetal A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

modern sperm whales (''Physeter macrocephalus'') have enamel on them before being coated with

, it is thought that the enamel is also an ancient characteristic ( basal). The appearance of raptorial sperm whales in the fossil record coincides with the diversification of

baleen whale Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankt ...

s in the

, implying that they evolved specifically to exploit baleen whales. It has also been suggested that the raptorial sperm whales should be placed into the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Hoplocetinae, alongside the genera ''

Diaphorocetus ''Diaphorocetus'' is an extinct genus of odontocete cetacean belonging to Physeteroidea. Its remains were found in the Monte León Formation of Argentina, dating to the Early Miocene.Idiorophus ''Idiorophus'' is a genus of extinct toothed whales in the family Physeteridae. Fossils have been found in the Colhuehuapian Gaiman Formation of Argentina and the Libano Sandstone in Italy. The teeth of ''Idiorophus'' were similar in size to ...

'', ''

Scaldicetus ''Scaldicetus'' is an extinct genus of highly predatory macroraptorial sperm whale. Although widely used for a number of extinct physeterids with primitive dental morphology consisting of enameled teeth, ''Scaldicetus'' as generally recognized ...

'' and ''

Hoplocetus ''Hoplocetus'' is an extinct genus of raptorial cetacean of the sperm whale superfamily (biology), superfamily, Physeteroidea. Its remains have been found in the Miocene of Belgium, France, Germany and Malta, the Pliocene of Belgium and France, a ...

'', which are known from the Miocene to the lower

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58wastebasket taxa Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the purpose of classifying organisms that do not fit anywhere else. They are typically defined by e ...

for non-diagnostic material of stem physeteroids. This subfamily is characterized by their robust and enamel-coated teeth. The cladograms below are modified from Lambert ''et al.'' (2017) and Paolucci et al. (2025), and represents the phylogenetic relationships between ''Livyatan'' and other sperm whales, with genera identified as macroraptorial sperm whales in bold.

Palaeobiology

Hunting

''Livyatan'' was an

, and probably had a profound impact on the structuring of Miocene marine communities. Using its large and deeply rooted teeth, it is likely to have hunted large prey near the surface, its diet probably consisting mainly of medium-sized baleen whales ranging from in length. It probably also preyed upon sharks, seals, dolphins and other large marine vertebrates, occupying a niche similar to the modern

killer whale The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopolit ...

(''Orcinus orca''). It was contemporaneous with and occupied the same region as the otodontid shark '' O. megalodon'', which was likely also an apex predator, implying

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

over their similar food sources. It is assumed that the hunting tactics of ''Livyatan'' for hunting whales were similar to that of the modern killer whale, pursuing prey to wear it out, and then drowning it. Modern killer whales work in groups to isolate and kill whales, but, given its size, ''Livyatan'' may have been able to hunt alone. Isotopic analysis of enamel from a tooth from Chile revealed that this individual likely operated at latitudes south of 40°S. Isotopic analyses of contemporary baleen whales in the same formation show that this ''Livyatan'' was not commonly feeding on them, indicating it probably did not exclusively eat large prey, though it may have targeted baleen whales from higher latitudes.

Spermaceti organ

The supracranial basin in its head suggests that ''Livyatan'' had a large

, a series of

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...

and

wax Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give lo ...

reservoirs separated by

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

. The uses for the spermaceti organ in ''Livyatan'' are unknown. Much like in the modern sperm whale, it could have been used in the process of

biosonar Echolocation, also called bio sonar, is a biological active sonar used by several animal groups, both in the air and underwater. Echolocating animals emit calls and listen to the echoes of those calls that return from various objects near them ...

to generate sound for locating prey. It is possible that it was also used as a means of acoustic displays, such as for communication purposes between individuals. It may have been used for acoustic stunning, which would have caused the bodily functions of a target animal to shut down from exposure to the intense sounds. Another theory says that the enlarged forehead caused by the presence of the spermaceti organ is used in all sperm whales between males fighting for females during mating season by head-butting each other, including ''Livyatan'' and the modern sperm whale. It may have also been used to ram into prey; if this is the case, in support of this, there have been two reports of modern sperm whales attacking whaling vessels by ramming into them, and the organ is disproportionally larger in male modern sperm whales. An alternate theory is that sperm whales, including ''Livyatan'', can alter the temperature of the wax in the organ to aid in buoyancy. Lowering the temperature increases the density to have it act as a weight for deep-sea diving, and raising the temperature decreases the density to have it pull the whale to the surface.

Palaeoecology

Fossils conclusively identified as ''L. melvillei'' have been found in Peru and Chile. However, additional isolated large sperm whale teeth from other locations including California, Australia, Argentina, South Africa and the Netherlands have been identified as a species or possible close relative of ''Livyatan''. On the basis of these fossils, it was likely that the distribution of ''Livyatan'' was widespread. Prior to 2023, paleontologists initially believed that the genus was restricted to the Southern Hemisphere. The warmer waters around the equator have been known to be a climatic barrier for numerous cetaceans since Neogene times, and it was then-hypothesized is that ''Livyatan'' may have been among the cetaceans unable to cross the equatorial barrier. However, collecting bias was another explanation given the apparent rarity and poor fossil record of ''Livyatan'', now supported by the Northern Hemisphere occurrence in California. The holotype of ''L. melvillei'' is from the

stage of the Upper

9.9–8.9 mya in the Pisco Formation of Peru, which is known for its well-preserved assemblage of marine vertebrates. Among the baleen whales found, the most common was an undescribed species of cetotheriid whale measuring around , and most of the other baleen whales found were roughly the same size. Toothed whale remains found consist of beaked whales (such as '' Messapicetus gregarius''), ancient pontoporiids (such as '' Brachydelphis mazeasi''),

oceanic dolphin Oceanic dolphins or Delphinidae are a widely distributed family of dolphins that live in the sea. Close to forty extant species are recognised. They include several big species whose common names contain "whale" rather than "dolphin", such as the ...

s and the raptorial sperm whale ''Acrophyseter''. All seal remains found represent the earless seals. Also found were large sea turtles such as '' Pacifichelys urbinai'', which points to the development of

seagrass Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and ...

es in this area. Partial bones of crocodiles were discovered. Of the seabirds, fragmentary bones of

cormorant Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the International Ornithologists' Union (IOU) ado ...

s and petrels were discovered, as well as two species of

boobies A booby is a seabird in the genus ''Sula'', part of the family Sulidae. Boobies are closely related to the gannets (''Morus''), which were formerly included in ''Sula''. Systematics and evolution The genus ''Sula'' was introduced by the Fre ...

. The remains of many

cartilaginous fish Chondrichthyes (; ) is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which have skeleto ...

were discovered in this formation, including more than 3,500 shark teeth, which mainly belonged to the ground sharks, such as requiem sharks and

hammerhead shark The hammerhead sharks are a group of sharks that form the family Sphyrnidae, named for the unusual and distinctive form of their heads, which are flattened and laterally extended into a Hammerhead shark#Cephalofoil, cephalofoil (a T-shape or " ...

s. To a lesser extent, mackerel sharks were also found, such as

white sharks The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large Lamniformes, mackerel shark which can be found in the coastal surface waters of all the major ocea ...

, sand sharks and

Otodontidae Otodontidae is an extinct family of sharks belonging to the order Lamniformes. Its members have been described as megatoothed sharks. They lived from the Early Cretaceous to the Pliocene, and included genera such as '' Otodus,'' including the gi ...

. Many shark teeth were associated with the extinct broad-tooth mako (''Cosmopolitodus/Carcharodon hastalis'') and megalodon, and the teeth of these two sharks were found near whale and seal remains.

Eagle ray The eagle rays are a group of cartilaginous fishes in the family Myliobatidae, consisting mostly of large species living in the open ocean rather than on the sea bottom. Eagle rays feed on mollusks, and crustaceans, crushing their shells with th ...

sawfish Sawfish, also known as carpenter sharks, are a family of very large rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the lar ...

and

angelshark Angel sharks are sharks belonging to the genus ''Squatina''. They are the only living members of the family Squatinidae and order Squatiniformes. They commonly inhabit sandy seabeds close to in depth. ''Squatina'' and other Squatiniformes d ...

s were other cartilaginous fish found. Most of the

bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...

findings belonged to

tuna A tuna (: tunas or tuna) is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae ( mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bul ...

s and croakers. ''Livyatan'' and megalodon were likely the apex predators of this area during this time. Livyatan melvillei

''L. melvillei'' is also known from the Bahía Inglesa Formation of Chile, whose fossiliferous beds are dated between the Tortonian and

Messinian The Messinian is in the geologic timescale the last age or uppermost stage of the Miocene. It spans the time between 7.246 ± 0.005 Ma and 5.333 ± 0.005 Ma (million years ago). It follows the Tortonian and is followed by the Zanclean, the fir ...

9.03–6.45 mya. Like the Pisco Formation, the Bahía Inglesa Formation famously holds one of the richest marine vertebrate assemblages. Baleen whale remains include ancient

minke whale The minke whale (), or lesser rorqual, is a species complex of baleen whale. The two species of minke whale are the common (or northern) minke whale and the Antarctic (or southern) minke whale. The minke whale was first described by the Danish na ...

grey whale The gray whale (''Eschrichtius robustus''), also known as the grey whale,Britannica Micro.: v. IV, p. 693. is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of , a weight of up to and lives between ...

bowhead whale The bowhead whale (''Balaena mysticetus''), sometimes called the Greenland right whale, Arctic whale, and polar whale, is a species of baleen whale belonging to the family Balaenidae and is the only living representative of the genus '' Balaena' ...

s and cetotheriids. Of the toothed whales, five species of pontoporiids as well as beaked whales,

porpoise Porpoises () are small Oceanic dolphin, dolphin-like cetaceans classified under the family Phocoenidae. Although similar in appearance to dolphins, they are more closely related to narwhals and Beluga whale, belugas than to the Oceanic dolphi ...

s, three other species of sperm whales such as ''cf. Scaldicetus'', and the '' Odobenocetops'' have been yielded. Other marine mammals include the marine sloth ''

Thalassocnus ''Thalassocnus'' is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—''T. antiquus'', ''T. natans'', ''T. lit ...

'' and pinnipeds like '' Acrophoca''. At least 28 different species of sharks have been described, including many extant ground sharks and white sharks as well as extinct species such as the false mako (''Parotodus sp.''), broad-toothed mako, megalodon and the transitional great white '' Carcharodon hubbelli''. Other marine vertebrates include

penguin Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...

s and other seabirds, and species of crocodiles and ghavials. The Beaumaris sperm whale was found in the

Black Rock Sandstone Formation in Australia near the city of

, dating to 5mya in the Pliocene. Beaumaris Bay is one of the most productive marine fossil sites in Australia for marine megafauna. Shark teeth belonging to twenty different species have been discovered there, such as from the

whale shark The whale shark (''Rhincodon typus'') is a slow-moving, filter feeder, filter-feeding carpet shark and the largest known Extant taxon, extant fish species. The largest confirmed individual had a length of . The whale shark holds many records for ...

(''Rhincodon typus''), the

Port Jackson shark The Port Jackson shark (''Heterodontus portusjacksoni'') is a nocturnal, oviparous (egg laying) type of bullhead shark of the family (biology) , family Bullhead shark , Heterodontidae, found in the coastal region of southern Australia, including ...

(''Heterodontus portusjacksoni''), the broad-toothed mako and megalodon. Some examples of whales found include the ancient humpback whale '' Megaptera miocaena'', the

dolphin A dolphin is an aquatic mammal in the cetacean clade Odontoceti (toothed whale). Dolphins belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontopori ...

'' Steno cudmorei'' and the sperm whale '' Physetodon baileyi''. Other large marine animals found include ancient

elephant seal Elephant seals or sea elephants are very large, oceangoing earless seals in the genus ''Mirounga''. Both species, the northern elephant seal (''M. angustirostris'') and the southern elephant seal (''M. leonina''), were hunted to the brink of ...

dugong The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest ...

s, sea turtles, ancient penguins such as '' Pseudaptenodytes'', the extinct albatross '' Diomedea thyridata'' and the extinct toothed seabirds of the genus '' Pelagornis''. The South African teeth attributed as ''cf. Livyatan'' are from the Avontuur Member of the Alexander Bay Formation near the village of Hondeklip Bay, Namaqualand, which is also dated to around 5mya in the Pliocene. The Hondeklip Bay locality enjoys a rich heritage of marine fossils, whose diversity may have been thanks to the initiation of the Benguela Upwelling during the late Miocene, which likely provided large populations of phytoplankton traveling the cold nutrient-rich waters. Cetaceans are the most abundant fauna in the bay, although remains tend to be difficult to conclusively identify. Included are three species of balaenopterids including two undetermined species and one identified as ''cf. Plesiobalaenoptera'', an ancient grey whale (''cf. Eschrichtius sp.''), an undetermined balaenid, an unidentified dolphin, and another undetermined species of macroraptorial sperm whale. Other localities of similar age on the South African west coast have also yielded many additional species of balaenopterids and sperm whales as well as ten species of beaked whales. Large sperm whale teeth of up to around ~ in length are common in Hondeklip Bay, indicating a high presence of large sperm whales like ''Livyatan'' in the area. The locality has also a high presence of sharks indicated by a large abundance of shark teeth; however, most of these teeth have not been identified. Megalodon teeth have been found in the bay, and evidence from bite marks in whale bones indicate the additional presence of the

great white shark The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large Lamniformes, mackerel shark which can be found in the coastal surface waters of all the major ocea ...

, shortfin mako and broad-toothed mako. Other marine fauna known in Hondeklip Bay include pinnipeds such as '' Homiphoca capensis'', bony fish and rays.

Extinction

''Livyatan''-like sperm whales became extinct by the early Pliocene likely due to a cooling trend causing baleen whales to increase in size and decrease in diversity, becoming

coextinct Coextinction and cothreatened refer to the phenomenon of the loss or decline of a host species resulting in the loss or endangerment of another species that depends on it, potentially leading to cascading effects across trophic levels. The term w ...

with the smaller whales they fed on. Their extinction also coincides with the emergence of the orcas as well as large predatory globicephaline dolphins, possibly acting as an additional stressor to their already collapsing niche.

Notes

References

External links

'Sea monster' fossil found in Peru desert
by

CNN Cable News Network (CNN) is a multinational news organization operating, most notably, a website and a TV channel headquartered in Atlanta. Founded in 1980 by American media proprietor Ted Turner and Reese Schonfeld as a 24-hour cable ne ...

Ancient sperm whale's giant head uncovered
from Los Angeles Times (The skull is on display in National History Museum in Lima)
A killer sperm whale
with details on sperm whale evolution ;Videos * * * (a collection of images of discovery) {{Taxonbar, from=Q131759 Miocene mammals of Africa Physeteroidea Prehistoric toothed whales Monotypic prehistoric cetacean genera Miocene cetaceans Miocene mammals of South America Neogene Peru Fossils of Peru Pisco Formation Fossil taxa described in 2010 Herman Melville Apex predators Leviathan