Megalodon (''Otodus megalodon''), meaning "big tooth", is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of mackerel shark that lived approximately 23 to 3.6

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago) ...

(Mya), from the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

to the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Lamnidae The Lamnidae are the family of mackerel sharks known as white sharks. They are large, fast-swimming predatory fish found in oceans worldwide, though prefer environments with colder water. The name of the family is formed from the Greek word ''la ...

and a close relative 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 ocean ...

(''Carcharodon carcharias''). However, it is now classified into the extinct family

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 ''Carcharocles'' and ''Otod ...

, which diverged from the great white shark during the Early Cretaceous. While regarded as one of the largest and most powerful predators to have ever lived, the megalodon is only known from fragmentary remains, and its appearance and maximum size are uncertain. Scientists differ on whether it would have more closely resembled a stockier version of the great white shark, the

whale shark The whale shark (''Rhincodon typus'') is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of .McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, ...

(''Rhincodon typus''), the

basking shark The basking shark (''Cetorhinus maximus'') is the second-largest living shark and fish, after the whale shark, and one of three plankton-eating shark species, along with the whale shark and megamouth shark. Adults typically reach in leng ...

(''Cetorhinus maximus'') or the sand tiger shark (''Carcharias taurus''). The most recent estimate with the least error range suggests a maximum length estimate up to , although the modal lengths are estimated at . Extrapolation from a vertebral centra with dimensions based on the

suggests that a megalodon about long weighs up to , long weighs up to , and long (the maximum length) weighs up to . Extrapolating from a

vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordate ...

and reconstructing a 3D model with dimensions based on all extant lamnid sharks suggests that a individual may have been much larger than previous estimates, reaching an excess of in body mass; an individual of this size would have needed to consume 98,175 kcal per day. Their teeth were thick and robust, built for grabbing prey and breaking bone, and their large jaws could exert a bite force of up to . Megalodon probably had a major impact on the structure of marine communities. The fossil record indicates that it had a cosmopolitan distribution. It probably targeted large prey, such as whales, seals and

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...

s. Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from the soft underside, megalodon probably used its strong jaws to break through the chest cavity and puncture the heart and lungs of its prey. The animal faced competition from whale-eating cetaceans, such as '' Livyatan'' and other macroraptorial sperm whales and possibly smaller ancestral killer whales. As the shark preferred warmer waters, it is thought that oceanic cooling associated with the onset of the

ice ages An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

, coupled with the lowering of sea levels and resulting loss of suitable nursery areas, may have also contributed to its decline. A reduction in the diversity of baleen whales and a shift in their distribution toward polar regions may have reduced megalodon's primary food source. The shark's extinction coincides with a gigantism trend in baleen whales.

Taxonomy

Naming

According to

Renaissance The Renaissance ( , ) , from , with the same meanings. is a period in European history The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (800 BC to AD ...

accounts, gigantic triangular fossil teeth often found embedded in rocky formations were once believed to be the petrified tongues, or glossopetrae, of dragons and

snake Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...

s. This interpretation was corrected in 1667 by Danish naturalist Nicolas Steno, who recognized them as

shark teeth Sharks continually shed their teeth; some Carcharhiniformes shed approximately 35,000 teeth in a lifetime, replacing those that fall out. There are four basic types of shark teeth: dense flattened, needle-like, pointed lower with triangular upp ...

, and famously produced a depiction of a

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

's head bearing such teeth. He described his findings in the book ''The Head of a Shark Dissected'', which also contained an illustration of a megalodon tooth. Swiss naturalist Louis Agassiz gave this shark its

initial In a written or published work, an initial capital, also referred to as a drop capital or simply an initial cap, initial, initcapital, initcap or init or a drop cap or drop, is a letter at the beginning of a word, a chapter, or a paragraph that ...

scientific name, ''Carcharodon megalodon'', in his 1843 work ''Recherches sur les poissons fossiles'', based on tooth remains. English

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Edward Charlesworth in his 1837 paper used the name ''Carcharias megalodon'', while citing Agassiz as the author, indicating that Agassiz described the species prior to 1843. English paleontologist Charles Davies Sherborn in 1928 listed an 1835 series of articles by Agassiz as the first scientific description of the shark. The specific name ''megalodon'' translates to "big tooth", from grc, μέγας, (mégas), big, mighty and ὀδούς (''odoús''), "tooth". The teeth of megalodon are morphologically similar to those of the

(''Carcharodon carcharias''), and on the basis of this observation, Agassiz assigned megalodon to the genus ''

Carcharodon ''Carcharodon'' () is a genus of sharks within the family Lamnidae. The only extant member is the great white shark (''Carcharodon carcharias''). Hubell's white shark ('' Carcharodon hubbelli'') is an extinct member of this genus. Megalodon ...

''. There was one apparent description of the shark in 1881 classifying it as ''Selache manzonii''.

Evolution

While the earliest megalodon remains have been reported from the

Late Oligocene The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/ Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

, around 28

(Mya), there is disagreement as to when it appeared, with dates ranging to as young as 16 mya. It has been thought that megalodon became extinct around the end of the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 claims of

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

megalodon teeth, younger than 2.6 million years old, are considered unreliable. A 2019 assessment moves the extinction date back to earlier in the Pliocene, 3.6 Mya. Megalodon is now considered to be a member of the family Otodontidae, genus ''Otodus'', as opposed to its previous classification into Lamnidae, genus ''Carcharodon''. Megalodon's classification into ''Carcharodon'' was due to dental similarity with the great white shark, but most authors currently believe that this is due to

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

. In this model, the great white shark is more closely related to the extinct broad-toothed mako ('' Isurus hastalis'') than to megalodon, as evidenced by more similar dentition in those two sharks; megalodon teeth have much finer serrations than great white shark teeth. The great white shark is more closely related to the mako shark (''Isurus'' spp.), with a

common ancestor Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal comm ...

around 4 Mya. Proponents of the former model, wherein megalodon and the great white shark are more closely related, argue that the differences between their dentition are minute and obscure. Megalodon tooth with great white sharks teeth-3-2

Megalodon tooth with great white sharks teeth-3-2

The genus ''Carcharocles'' currently contains four species: '' C. auriculatus'', '' C. angustidens'', '' C. chubutensis'', and ''C. megalodon''. The evolution of this lineage is characterized by the increase of serrations, the widening of the crown, the development of a more triangular shape, and the disappearance of the

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction * Lateral cricoarytenoid muscle * Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ...

cusps. The evolution in tooth morphology reflects a shift in predation tactics from a tearing-grasping bite to a cutting bite, likely reflecting a shift in prey choice from fish to cetaceans. Lateral cusplets were finally lost in a gradual process that took roughly 12 million years during the transition between ''C. chubutensis'' and ''C. megalodon''. The genus was proposed by D. S. Jordan and H. Hannibal in 1923 to contain ''C. auriculatus''. In the 1980s, megalodon was assigned to ''Carcharocles''. Before this, in 1960, the genus ''Procarcharodon'' was erected by French ichthyologist Edgard Casier, which included those four sharks and was considered separate from the great white shark. It is now considered a junior synonym of ''Carcharocles''. The genus '' Palaeocarcharodon'' was erected alongside ''Procarcharodon'' to represent the beginning of the lineage, and, in the model wherein megalodon and the great white shark are closely related, their last common ancestor. It is believed to be an evolutionary dead-end and unrelated to the ''Carcharocles'' sharks by authors who reject that model.

Another model of the evolution of this genus, also proposed by Casier in 1960, is that the direct ancestor of the ''Carcharocles'' is the shark ''

Otodus obliquus ''Otodus'' is an extinct genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name ''Otodus'' comes from Ancient Greek (, meaning "ear") and (, meaning "tooth") – thus, "ear-shaped tooth". Anatomy This shark is k ...

'', which lived from the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

through 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 ...

epochs, 60 to 13 Mya. The genus ''Otodus'' is ultimately derived from '' Cretolamna'', a shark from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

period. In this model, ''O. obliquus'' evolved into ''O. aksuaticus'', which evolved into ''C. auriculatus'', and then into ''C. angustidens'', and then into ''C. chubutensis'', and then finally into ''C. megalodon''. Another model of the evolution of ''Carcharocles'', proposed in 2001 by paleontologist Michael Benton, is that the three other species are actually a single species of shark that gradually changed over time between the Paleocene and the Pliocene, making it a

chronospecies A chronospecies is a species derived from a sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a population that is p ...

. Some authors suggest that ''C. auriculatus'', ''C. angustidens'', and ''C. chubutensis'' should be classified as a single species in the genus ''Otodus'', leaving ''C. megalodon'' the sole member of ''Carcharocles''. The genus ''Carcharocles'' may be invalid, and the shark may actually belong in the genus ''Otodus'', making it ''Otodus megalodon''. A 1974 study on Paleogene sharks by

Henri Cappetta Henri Cappetta is a French ichthyologist specializing in the paleontology of sharks and rays. References * H. Cappetta, Handbook of Paleoichthyology The evolution of fish began about 530 million years ago during the Cambrian explosion. It w ...

erected the subgenus ''Megaselachus'', classifying the shark as ''Otodus'' (''Megaselachus'') ''megalodon'', along with ''O. (M.) chubutensis''. A 2006 review of

Chondrichthyes Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. ...

elevated ''Megaselachus'' to genus, and classified the sharks as ''Megaselachus megalodon'' and ''M. chubutensis''. The discovery of fossils assigned to the genus '' Megalolamna'' in 2016 led to a re-evaluation of ''Otodus'', which concluded that it is paraphyletic, that is, it consists of a

last common ancestor In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...

but it does not include all of its descendants. The inclusion of the ''Carcharocles'' sharks in ''Otodus'' would make it monophyletic, with the sister clade being ''Megalolamna''. The cladogram below represents the hypothetical relationships between megalodon and other sharks, including the great white shark. Modified from Shimada et al. (2016), Ehret et al, (2009), and the findings of Siversson et al. (2013).

Biology

Appearance

One interpretation on how megalodon appeared was that it was a robust-looking shark, and may have had a similar build to the great white shark. The jaws may have been blunter and wider than the great white, and the fins would have also been similar in shape, though thicker due to its size. It may have had a pig-eyed appearance, in that it had small, deep-set eyes. Another interpretation is that megalodon bore a similarity to the

(''Rhincodon typus'') or the

(''Cetorhinus maximus''). The tail fin would have been crescent-shaped, the anal fin and second dorsal fin would have been small, and there would have been a caudal keel present on either side of the tail fin (on the

caudal peduncle Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

). This build is common in other large aquatic animals, such as whales, tuna, and other sharks, in order to reduce drag while swimming. The head shape can vary between species as most of the drag-reducing adaptations are toward the tail-end of the animal. 2016 megalodon

Since ''Carcharocles'' is derived from ''Otodus'', and the two had teeth that bear a close similarity to those of the sand tiger shark (''Carcharias taurus''), megalodon may have had a build more similar to the sand tiger shark than to other sharks. This is unlikely since the sand tiger shark is a carangiform swimmer which requires faster movement of the tail for propulsion through the water than the great white shark, a thunniform swimmer.

Size

Due to fragmentary remains, there have been many contradictory size estimates for megalodon, as they can only be drawn from fossil teeth and vertebrae. The great white shark has been the basis of reconstruction and size estimation, as it is regarded as the best analogue to megalodon. Several total length estimation methods have been produced from comparing megalodon teeth and vertebrae to those of the great white. Megalodon size estimates vary depending on the method used, with maximum total length estimates ranging from . A 2015 study estimated the average total body length at , calculated from 544 megalodon teeth, found throughout geological time and geography, including adults and juveniles. In comparison, large great white sharks are generally around in length, with a few contentious reports suggesting larger sizes. The whale shark is the largest living fish, with one large female reported with a precaudal length of and an estimated total length of . It is possible that different populations of megalodon around the globe had different body sizes and behaviors due to different ecological pressures. Megalodon is thought to have been the largest macropredatory shark that ever lived. In his 2015 book, ''The Story of Life in 25 Fossils: Tales of Intrepid Fossil Hunters and the Wonders of Evolution'', Donald Prothero proposed the body mass estimates for different individiuals of different length by extrapolating from a vertebral centra based on the dimensions of the great white, a methodology also used for the 2008 study which supports the maximum mass estimate. In 2020, Cooper and his colleagues reconstructed a 2D model of megalodon based on the dimensions of all the extant lamnid sharks and suggested that a long megalodon would have had a long head, tall gill slits, a tall dorsal fin, long pectoral fins, and a tall tail fin. In 2022, Cooper and his colleagues also reconstructed a 3D model with the same basis as the 2020 study, resulting in a body mass estimate of for a long megalodon (higher than the previous estimates); a

specimen named IRSNB P 9893 (formerly IRSNB 3121), belonging to a 46 year old individual from

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

, was used for extrapolation. An individual of this size would have required 98,175 kcal per day, 20 times more than what the adult great white requires. Mature male megalodon may have had a body mass of , and mature females may have been , assuming that males could range in length from and females . A 2015 study linking shark size and typical swimming speed estimated that megalodon would have typically swum at –assuming that its body mass was typically –which is consistent with other aquatic creatures of its size, such as the

fin whale The fin whale (''Balaenoptera physalus''), also known as finback whale or common rorqual and formerly known as herring whale or razorback whale, is a cetacean belonging to the parvorder of baleen whales. It is the second-longest species of ce ...

(''Balaenoptera physalus'') which typically cruises at speeds of . In 2022, Cooper and his colleagues converted this calculation into relative cruising speed (body lengths per second), resulting in an mean absolute crusing speed of and a mean relative cruising speed of 0.09 body lengths per second for a long megalodon; the authors found their mean absolute cruising speed to be faster than any extant lamnid sharks and their mean relative cruising speed to be slower, consistent with previous estiamtes. Its large size may have been due to climatic factors and the abundance of large prey items, and it may have also been influenced by the evolution of regional endothermy (mesothermy) which would have increased its

metabolic rate Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run ce ...

and swimming speed. The otodontid sharks have been considered to have been

ectotherm An ectotherm (from the Greek () "outside" and () "heat") is an organism in which internal physiological sources of heat are of relatively small or of quite negligible importance in controlling body temperature.Davenport, John. Animal Life ...

s, so on that basis megalodon would have been ectothermic. However, the largest contemporary ectothermic sharks, such as the whale shark, are filter feeders, while lamnids are now known to be regional endotherms, implying some metabolic correlations with a predatory lifestyle. These considerations, as well as tooth oxygen isotopic data and the need for higher burst swimming speeds in macropredators of endothermic prey than ectothermy would allow, imply that otodontids, including megalodon, were probably regional endotherms. In 2020, Shimada and colleagues suggested large size was instead due to intrauterine cannibalism, where the larger fetus eats the smaller fetus, resulting in progressively larger and larger fetuses, requiring the mother to attain even greater size as well as caloric requirements which would have promoted endothermy. Males would have needed to keep up with female size in order to still effectively copulate (which probably involved latching onto the female with

clasper In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating. Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve to channel semen into the female's c ...

s, like modern cartilaginous fish).

Maximum estimates

The first attempt to reconstruct the jaw of megalodon was made by

Bashford Dean Bashford Dean (October 28, 1867 – December 6, 1928) was an American zoologist, specializing in ichthyology, and at the same time an expert in medieval and modern armor. He is the only person to have held concurrent positions at the America ...

in 1909, displayed at the American Museum of Natural History. From the dimensions of this jaw reconstruction, it was hypothesized that megalodon could have approached in length. Dean had overestimated the size of the cartilage on both jaws, causing it to be too tall. In 1973, John E. Randall, an ichthyologist, used the enamel height (the vertical distance of the blade from the base of the enamel portion of the tooth to its tip) to measure the length of the shark, yielding a maximum length of about . However, tooth enamel height does not necessarily increase in proportion to the animal's total length. In 1994, marine biologists Patrick J. Schembri and Stephen Papson opined that ''O. megalodon'' may have approached a maximum of around in total length. In 1996, shark researchers Michael D. Gottfried,

Leonard Compagno Leonard Joseph Victor Compagno is an international authority on shark taxonomy and the author of many scientific papers and books on the subject, best known of which is his 1984 catalogue of shark species produced for the Food and Agriculture Organ ...

, and S. Curtis Bowman proposed a linear relationship between the great white shark's total length and the height of the largest upper anterior tooth. The proposed relationship is: total length in meters = − (0.096) × mm).html" ;"title="Millimetre.html" ;"title="A maximum height (Millimetre">mm)">Millimetre.html" ;"title="A maximum height (Millimetre">mm)(0.22). Using this tooth height regression equation, the authors estimated a total length of based on a tooth tall, which the authors considered a conservative maximum estimate. They also compared the ratio between the tooth height and total length of large female great whites to the largest megalodon tooth. A long female great white, which the authors considered the largest 'reasonably trustworthy' total length, produced an estimate of . However, based on the largest female great white reported, at , they estimated a maximum estimate of . In 2002, shark researcher Clifford Jeremiah proposed that total length was proportional to the root width of an upper anterior tooth. He claimed that for every of root width, there are approximately of shark length. Jeremiah pointed out that the jaw perimeter of a shark is directly proportional to its total length, with the width of the roots of the largest teeth being a tool for estimating jaw perimeter. The largest tooth in Jeremiah's possession had a root width of about , which yielded in total length. In 2002, paleontologist Kenshu Shimada of DePaul University proposed a linear relationship between tooth crown height and total length after conducting anatomical analysis of several specimens, allowing any sized tooth to be used. Shimada stated that the previously proposed methods were based on a less-reliable evaluation of the dental homology between megalodon and the great white shark, and that the growth rate between the crown and root is not isometric, which he considered in his model. Using this model, the upper anterior tooth possessed by Gottfried and colleagues corresponded to a total length of . Among several specimens found in the Gatún Formation of Panama, one upper lateral tooth was used by other researchers to obtain a total length estimate of using this method. In 2019, Shimada revisited the size of megalodon and discouraged using non-anterior teeth for estimations, noting that the exact position of isolated non-anterior teeth is difficult to identify. Shimada provided maximum total length estimates using the largest anterior teeth available in museums. The tooth with the tallest crown height known to Shimada, NSM PV-19896, produced a total length estimate of . The tooth with the tallest total height, FMNH PF 11306, was reported at . However, Shimada remeasured the tooth and found it actually to measure . Using the total height tooth regression equation proposed by Gottfried and colleagues produced an estimate of . In 2021, Victor J. Perez, Ronny M. Leder, and Teddy Badaut proposed a method of estimating total length of megalodon from the sum of the tooth crown widths. Using more complete megalodon dentitions, they reconstructed the dental formula and then made comparisons to living sharks. The researchers noted that the 2002 Shimada crown height equations produce wildly varying results for different teeth belonging to the same shark (range of error of ± ), casting doubt on some of the conclusions of previous studies using that method. Using the largest tooth available to the authors, GHC 6, with a crown width of , they estimated a maximum body length of approximately , with a range of error of approximately ± . This maximum length estimate was also supported by Cooper and his colleagues in 2022. There are anecdotal reports of teeth larger than those found in museum collections. Gordon Hubbell from Gainesville, Florida, possesses an upper anterior megalodon tooth whose maximum height is , one of the largest known tooth specimens from the shark. In addition, a megalodon jaw reconstruction developed by fossil hunter Vito Bertucci contains a tooth whose maximum height is reportedly over .

Teeth and bite force

The most common fossils of megalodon are its teeth. Diagnostic characteristics include a triangular shape, robust structure, large size, fine serrations, a lack of lateral denticles, and a visible V-shaped neck (where the

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...

meets the

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

). The tooth met the jaw at a steep angle, similar to the great white shark. The tooth was anchored by connective tissue fibers, and the roughness of the base may have added to mechanical strength. The lingual side of the tooth, the part facing the tongue, was convex; and the labial side, the other side of the tooth, was slightly convex or flat. The anterior teeth were almost perpendicular to the jaw and symmetrical, whereas the posterior teeth were slanted and asymmetrical. Megalodon teeth can measure over in slant height (diagonal length) and are the largest of any known shark species, implying it was the largest of all macropredatory sharks. In 1989, a nearly complete set of megalodon teeth was discovered in

Saitama, Japan is the capital and the most populous city of Saitama Prefecture, Japan. Its area incorporates the former cities of Urawa, Ōmiya, Yono and Iwatsuki. It is a city designated by government ordinance. Being in the Greater Tokyo Area and lying ...

. Another nearly complete associated megalodon dentition was excavated from the Yorktown Formations in the United States, and served as the basis of a jaw reconstruction of megalodon at the

National Museum of Natural History The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7 ...

(USNM). Based on these discoveries, an artificial

dental formula Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiolog ...

was put together for megalodon in 1996. The dental formula of megalodon is: . As evident from the formula, megalodon had four kinds of teeth in its jaws: anterior, intermediate, lateral, and posterior. Megalodon's intermediate tooth technically appears to be an upper anterior and is termed as "A3" because it is fairly symmetrical and does not point mesially (side of the tooth toward the midline of the jaws where the left and right jaws meet). Megalodon had a very robust dentition, and had over 250 teeth in its jaws, spanning 5 rows. It is possible that large megalodon individuals had jaws spanning roughly across. The teeth were also

serrated Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied p ...

, which would have improved efficiency in cutting through flesh or bone. The shark may have been able to open its mouth to a 75° angle, though a reconstruction at the USNM approximates a 100° angle. Megalodon jaws on display at the National Baltimore Aquarium

Megalodon jaws on display at the National Baltimore Aquarium

In 2008, a team of scientists led by S. Wroe conducted an experiment to determine the bite force of the great white shark, using a long specimen, and then isometrically scaled the results for its maximum size and the conservative minimum and maximum body mass of megalodon. They placed the bite force of the latter between in a posterior bite, compared to the bite force for the largest confirmed great white shark, and for the placoderm fish ''

Dunkleosteus ''Dunkleosteus'' is an extinct genus of large armored, jawed fishes that existed during the Late Devonian period, about 382–358 million years ago. It consists of ten species, some of which are among the largest placoderms to have ever lived: ...

''. In addition, Wroe and colleagues pointed out that sharks shake sideways while feeding, amplifying the force generated, which would probably have caused the total force experienced by prey to be higher than the estimate. In 2021, Antonio Ballell and Humberto Ferrón used Finite Element Analysis modeling to examine the stress distribution of three types of megalodon teeth and closely related mega-toothed species when exposed to anterior and lateral forces, the latter of which would be generated when a shark shakes its head to tear through flesh. The resulting simulations identified higher levels of stress in megalodon teeth under lateral force loads compared to its precursor species such as ''O. obliquus'' and ''O. angusteidens'' when tooth size was removed as a factor. This suggests that megalodon teeth were of a different functional significance than previously expected, challenging prior interpretations that megalodon's dental morphology was primarily driven by a dietary shift towards marine mammals. Instead, the authors proposed that it was a byproduct of an increase in body size caused by heterochronic selection.

Internal anatomy

Megalodon is represented in the fossil record by teeth, vertebral centra, and coprolites. As with all sharks, the skeleton of megalodon was formed of cartilage rather than

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

; consequently most fossil specimens are poorly preserved. To support its large dentition, the jaws of megalodon would have been more massive, stouter, and more strongly developed than those of the great white, which possesses a comparatively gracile dentition. Its chondrocranium, the cartilaginous skull, would have had a blockier and more robust appearance than that of the great white. Its fins were proportional to its larger size. Some fossil

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

e have been found. The most notable example is a partially preserved vertebral column of a single specimen, excavated in the Antwerp Basin, Belgium, in 1926. It comprises 150 vertebral

centra Centra is a convenience shop chain that operates throughout Ireland. The chain operates as a symbol group owned by Musgrave Group, the food wholesaler, meaning the stores are all owned by individual franchisees. The chain has three different ...

, with the centra ranging from to in diameter. The shark's vertebrae may have gotten much bigger, and scrutiny of the specimen revealed that it had a higher vertebral count than specimens of any known shark, possibly over 200 centra; only the great white approached it. Another partially preserved vertebral column of a megalodon was excavated from the Gram Formation in Denmark in 1983, which comprises 20 vertebral centra, with the centra ranging from to in diameter. The coprolite remains of megalodon are spiral-shaped, indicating that the shark may have had a

spiral valve A spiral valve or scroll valve is the corkscrew-shaped lower portion of the intestine of some sharks, Acipenseriformes (sturgeon and paddlefish), rays, skates, bichirs, Lepisosteiformes (gars), and lungfishes. A modification of the ileum, the s ...

, a corkscrew-shaped portion of the lower intestines, similar to extant lamniform sharks. Miocene coprolite remains were discovered in

Beaufort County, South Carolina Beaufort County ( ) is a county in the U.S. state of South Carolina. As of the 2020 census, its population was 187,117. Its county seat is Beaufort. Beaufort County is part of the Hilton Head Island-Bluffton-Beaufort, SC Metropolitan Stati ...

, with one measuring . Gottfried and colleagues reconstructed the entire skeleton of megalodon, which was later put on display at the

Calvert Marine Museum The Calvert Marine Museum is a maritime museum located in Solomons, Maryland. The museum has three main themes: * regional paleontology, * estuarine life of the Patuxent River and Chesapeake Bay, * maritime history. Among its exhibits are the ...

in the United States and the

Iziko South African Museum The Iziko South African 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 site in the Company's Garden since 1897. The museum houses important ...

. This reconstruction is long and represents a mature male, based on the

ontogenetic Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the st ...

changes a great white shark experiences over the course of its life.

Paleobiology

Range and habitat

Megalodon had a cosmopolitan distribution; its fossils have been excavated from many parts of the world, including Europe, Africa, the Americas, and Australia. It most commonly occurred in subtropical to

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...

latitudes. It has been found at latitudes up to 55° N; its inferred tolerated temperature range was . It arguably had the capacity to endure such low temperatures due to mesothermy, the physiological capability of large sharks to maintain a higher body temperature than the surrounding water by conserving metabolic heat. Megalodon inhabited a wide range of marine environments (i.e., shallow coastal waters, areas of coastal

upwelling Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nut ...

, swampy coastal

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') ...

s, sandy

littoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal a ...

s, and offshore deep water environments), and exhibited a transient lifestyle. Adult megalodon were not abundant in shallow water environments, and mostly inhabited offshore areas. Megalodon may have moved between coastal and oceanic waters, particularly in different stages of its life cycle. Fossil remains show a trend for specimens to be larger on average in the Southern Hemisphere than in the Northern, with mean lengths of , respectively; and also larger in the Pacific than the Atlantic, with mean lengths of respectively. They do not suggest any trend of changing body size with absolute latitude, or of change in size over time (although the ''Carcharocles'' lineage in general is thought to display a trend of increasing size over time). The overall modal length has been estimated at , with the length distribution skewed towards larger individuals, suggesting an ecological or competitive advantage for larger body size.

Locations of fossils

Megalodon had a global distribution and fossils of the shark have been found in many places around the world, bordering all oceans of the Neogene. {{Location map+ , World , AlternativeMap=Land shallow topo 2048.jpg , relief = 1 , width = 800 , float = center , caption = Locations of megalodon fossil discoveries, yellow from the Pliocene and blue from the Miocene , places = {{Location map~ , Africa , lat_deg = -4.5 , lon_deg = 18.7 , mark = Yellow pog.svg , marksize = 7 {{Location map~ , Africa , lat_deg = 14.5 , lon_deg = 19.5 , mark = Yellow pog.svg , marksize = 7 {{Location map~ , Africa , lat_deg = -13.5 , lon_deg = 20.5 , mark = Yellow pog.svg , marksize = 7 {{Location map~ , World , coordinates ={{Coord, 44.8, N, 9.9, E , mark = Yellow pog.svg , marksize = 7 {{Location map~ , World , coordinates ={{Coord, 37.4, N, 6.6, W , mark = Yellow pog.svg , marksize = 7 {{Location map~ , World , coordinates ={{Coord, 38.1, N, 8.4, W , mark = Yellow pog.svg , marksize = 7 {{Location map~ , 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Prey relationships

Though sharks are generally opportunistic feeders, megalodon's great size, high-speed swimming capability, and powerful jaws, coupled with an impressive feeding apparatus, made it an

apex predator An apex predator, also known as a top predator, 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 highest trophic lev ...

capable of consuming a broad spectrum of animals. Otodus megalodon was probably one of the most powerful predators to have existed. A study focusing on calcium isotopes of extinct and extant

elasmobranch Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of g ...

sharks and rays revealed that megalodon fed at a higher

trophic level The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it ...

than the contemporaneous great white shark ("higher up" in the

food chain A food chain is a linear network of links in a food web starting from producer organisms (such as grass or algae which produce their own food via photosynthesis) and ending at an apex predator species (like grizzly bears or killer whales), de ...

.){{cite journal, last1= Martin, first1= J. E., last2= Tacail, first2=T., last3=Sylvain, first3=A., last4=Catherine, first4= G., last5= Vincent, first5= B., title=Calcium isotopes reveal the trophic position of extant and fossil elasmobranchs, journal=Chemical Geology, year=2015, pages= 118–125 , doi=10.1016/j.chemgeo.2015.09.011, volume=415, bibcode= 2015ChGeo.415..118M Fossil evidence indicates that megalodon preyed upon many cetacean species, such as dolphins, small whales, cetotheres, squalodontids (shark toothed dolphins),

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 fam ...

, bowhead whales, and rorquals.{{cite journal, last=Morgan, first=Gary S., title=Whither the giant white shark?, url=https://www.priweb.org/files/pubtext/item_pdf_289.pdf, journal=Paleontology Topics, year=1994, volume=2, issue=3, pages=1–2, url-status=dead, archive-url=https://web.archive.org/web/20160722045756/https://www.priweb.org/files/pubtext/item_pdf_289.pdf, archive-date=22 July 2016 In addition to this, they also targeted seals, sirenians, and sea turtles. The shark was an opportunist and

piscivorous A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

, and it would have also gone after smaller fish and other sharks.{{cite book, chapter-url={{google books, plainurl=yes, id=QjkjBQAAQBAJ, page=96, first=D. R., last=Prothero, year=2015, title=The Story of Life in 25 Fossils, chapter=Mega-Jaws, publisher=

Columbia University Press Columbia University Press is a university press based in New York City, and affiliated with Columbia University. It is currently directed by Jennifer Crewe (2014–present) and publishes titles in the humanities and sciences, including the fiel ...

, location=New York, New York, pages=96–110, isbn=978-0-231-17190-8, oclc=897505111 Many whale bones have been found with deep gashes most likely made by their teeth.{{rp, 75 Various excavations have revealed megalodon teeth lying close to the chewed remains of whales,{{rp, 75 and sometimes in direct association with them.{{cite journal , last1=Augilera , first1=Orangel A. , last2=García , first2=Luis , last3=Cozzuol , first3=Mario A. , year=2008 , title=Giant-toothed white sharks and cetacean trophic interaction from the Pliocene Caribbean Paraguaná Formation , journal=Paläontologische Zeitschrift , volume=82 , issue=2 , pages=204–208 , doi=10.1007/BF02988410 , issn=0038-2353 , s2cid=84251638 The feeding ecology of megalodon appears to have varied with age and between sites, like the modern

. It is plausible that the adult megalodon population off the coast of

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

targeted primarily cetothere whales {{convert, 2.5, to, 7, m, ft, sp=us, sigfig=2 in length and other prey smaller than itself, rather than large whales in the same size class as themselves.{{cite journal , first1 = A. , last1 = Collareta , first2 = O. , last2 = Lambert , first3 = W. , last3 = Landini , first4 = C. , last4 = Di Celma , first5 = E. , last5 = Malinverno , first6 = R. , last6 = Varas-Malca , first7 = M. , last7 = Urbina , first8 = G. , last8 = Bianucci , title = Did the giant extinct shark ''Carcharocles megalodon'' target small prey? Bite marks on marine mammal remains from the late Miocene of Peru , journal = Palaeogeography, Palaeoclimatology, Palaeoecology , volume = 469 , pages = 84–91 , doi = 10.1016/j.palaeo.2017.01.001 , year = 2017 , bibcode = 2017PPP...469...84C, hdl = 10281/151854 Meanwhile, juveniles likely had a diet that consisted more of fish.{{cite journal , first1 = W. , last1 = Landini , first2 = A. , last2 = Altamirano-Sera , first3 = A. , last3 = Collareta , first4 = C. , last4 = Di Celma , first5 = M. , last5 = Urbina , first6 = G. , last6 = Bianucci , title = The late Miocene elasmobranch assemblage from Cerro Colorado (Pisco Formation, Peru) , year = 2017 , volume = 73 , pages = 168–190 , journal = Journal of South American Earth Sciences , doi = 10.1016/j.jsames.2016.12.010 , bibcode = 2017JSAES..73..168L

Competition

Megalodon faced a highly

competitive 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, indivi ...

environment.{{Cite journal, doi= 10.1038/nature09067, last1=Lambert, first1=O., last2=Bianucci, first2=G., last3=Post, first3= P., last4=de Muizon, first4=C., last5=Salas-Gismondi, first5=R., last6=Urbina, first6=M., last7=Reumer, first7=J., title=The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru, journal= Nature, volume= 466, issue= 7302, pages=105–108, year=2010, pmid=20596020, bibcode = 2010Natur.466..105L , s2cid=4369352 Its position at the top of the food chain{{Cite journal, doi=10.1007/BF00751027, last=Compagno, first=Leonard J. V., title = Alternative life-history styles of cartilaginous fishes in time and space, journal=Environmental Biology of Fishes, volume=28, issue=1–4, pages=33–75, year=1989, s2cid=22527888 probably had a significant impact on the structuring of marine communities. Fossil evidence indicates a correlation between megalodon and the emergence and diversification of cetaceans and other marine mammals.{{rp, 78 Juvenile megalodon preferred habitats where small cetaceans were abundant, and adult megalodon preferred habitats where large cetaceans were abundant. Such preferences may have developed shortly after they appeared in the Oligocene.{{rp, 74–75 Megalodon were contemporaneous with whale-eating toothed whales (particularly macroraptorial sperm whales and squalodontidae), which were also probably among the era's apex predators, and provided competition. Some attained gigantic sizes, such as '' Livyatan'', estimated between {{convert, 13.5, to, 17.5, m, ft, sp=us. Fossilized teeth of an undetermined species of such physeteroids from Lee Creek Mine, North Carolina, indicate it had a maximum body length of 8–10 m and a maximum lifespan of about 25 years. This is very different from similarly sized modern killer whales that live to 65 years, suggesting that unlike the latter, which are apex predators, these physeteroids were subject to predation from larger species such as megalodon or ''Livyatan''.{{cite journal, last1=Gilbert, first1=K.N., last2=Ivany, first2=L.C., author-link2=Linda Ivany , last3=Uhen, first3=M.D., year=2018, title=Living fast and dying young: life history and ecology of a Neogene sperm whale, journal=Journal of Vertebrate Paleontology, volume=38, issue=2, pages=e1439038, doi=10.1080/02724634.2018.1439038, s2cid=89750852 By the Late Miocene, around 11 Mya, macroraptorials experienced a significant decline in abundance and diversity. Other species may have filled this niche in the Pliocene,{{Cite journal, last1=Heyning, first1=John, last2=Dahlheim, first2=Marilyn, title=Orcinus orca, journal=Mammalian Species, issue=304, pages=1–9, year=1988, url=http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-304-01-0001.pdf, doi=10.2307/3504225, jstor=3504225, s2cid=253914153 , url-status=dead, archive-url=https://web.archive.org/web/20101205083613/http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-304-01-0001.pdf, archive-date=5 December 2010 such as the fossil killer whale '' Orcinus citoniensis'' which may have been a pack predator and targeted prey larger than itself, but this inference is disputed, and it was probably a generalist predator rather than a marine mammal specialist.{{cite journal, url=https://www.researchgate.net/publication/244994854, first= G., last= Bianucci, year= 1997, title= ''Hemisyntrachelus cortesii'' (Cetacea, Delphinidae) from the Pliocene Sediments of Campore Quarry (Salsomaggiori Terme, Italy, journal= Bollettino della Societa Paleontologica Italiana, volume= 36, issue= 1, pages= 75–83) Megalodon may have subjected contemporaneous white sharks to

competitive exclusion In ecology, the competitive exclusion principle, sometimes referred to as Gause's law, is a proposition that two species which compete for the same limited resource cannot coexist at constant population values. When one species has even the sligh ...

, as the fossil records indicate that other shark species avoided regions it inhabited by mainly keeping to the colder waters of the time.{{Cite journal, last1=Antunes, first1=M.T., last2=Legoinha, first2=P., last3=Balbing, first3=A., title=Megalodon, mako shark and planktonic foraminifera from the continental shelf off Portugal and their age, journal=Geologica Acta, volume=13, pages=181–190, year=2015, url=http://dspace.uevora.pt/rdpc/handle/10174/17685{{rp, 77 In areas where their ranges seemed to have overlapped, such as in Pliocene

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, it is possible that megalodon and the great white shark occupied the area at different times of the year while following different migratory prey.{{rp, 77 Megalodon probably also had a tendency for cannibalism, much like contemporary sharks.

Feeding strategies

Sharks often employ complex hunting strategies to engage large prey animals. Great white shark hunting strategies may be similar to how megalodon hunted its large prey.{{cite journal, url=http://www.vmnh.net/content/File/Research_and_Collections/Jeffersoniana_Number_16.pdf, first1=S. J., last1=Godfrey, first2=J., last2=Altman, year=2005, title=A Miocene Cetacean Vertebra Showing a Partially Healed Compression Factor, the Result of Convulsions or Failed Predation by the Giant White Shark, ''Carcharodon megalodon'', journal=Jeffersoniana, number=16, pages=1–12 Megalodon bite marks on whale fossils suggest that it employed different hunting strategies against large prey than the great white shark. One particular specimen–the remains of a {{convert, 9, m, ft, sp=us, adj=on long undescribed Miocene baleen whale–provided the first opportunity to quantitatively analyze its attack behavior. Unlike great whites which target the underbelly of their prey, megalodon probably targeted the heart and lungs, with their thick teeth adapted for biting through tough bone, as indicated by bite marks inflicted to the rib cage and other tough bony areas on whale remains. Furthermore, attack patterns could differ for prey of different sizes. Fossil remains of some small cetaceans, for example cetotheres, suggest that they were rammed with great force from below before being killed and eaten, based on compression fractures. There is also evidence that a possible separate hunting strategy existed for attacking raptorial sperm whales; a tooth belonging to an undetermined {{convert, 4, m, ft, abbr=on physeteroid closely resembling those of ''

Acrophyseter ''Acrophyseter'' is a genus of extinct sperm whales that lived in the Late Miocene off the coast of Peru comprising two species: ''A. deinodon'' and ''A. robustus''. It is part of a group of macroraptorial sperm whales which all shared several ...

'' discovered in the Nutrien Aurora Phosphate Mine in North Carolina suggests that a megalodon or ''O. chubutensis'' may have aimed for the head of the sperm whale in order to inflict a fatal bite, the resulting attack leaving distinctive bite marks on the tooth. While scavenging behavior cannot be ruled out as a possibility, the placement of the bite marks is more consistent with predatory attacks than feeding by scavenging, as the jaw is not a particularly nutritious area to for a shark feed or focus on. The fact that the bite marks were found on the tooth's roots further suggest that the shark broke the whale's jaw during the bite, suggesting the bite was extremely powerful. The fossil is also notable as it stands as the first known instance of an antagonistic interaction between a sperm whale and an otodontid shark recorded in the fossil record. During the Pliocene, larger cetaceans appeared.{{cite journal, last1=Deméré, first1=Thomas A., last2=Berta, first2=Annalisa, last3=McGowen, first3=Michael R., year=2005, title=The taxonomic and evolutionary history of fossil and modern balaenopteroid mysticetes, journal=Journal of Mammalian Evolution, volume=12, issue=1/2, pages=99–143, doi=10.1007/s10914-005-6944-3, s2cid=90231 Megalodon apparently further refined its hunting strategies to cope with these large whales. Numerous fossilized flipper bones and tail vertebrae of large whales from the Pliocene have been found with megalodon bite marks, which suggests that megalodon would immobilize a large whale before killing and feeding on it.

Growth and reproduction

In 2021, Shimada and colleagues calculated the growth rate of an approximately {{cvt, 9.2, m individual based on the Belgian vertebrate column specimen that presumably contains annual growth rings on three of its vertebrae. They estimated the individual died at 46 years of age, with a growth rate of {{cvt, 16, cm per year, and a length of {{cvt, 2, m at birth. For a {{cvt, 15, m individual—which they considered to have been the maximum size attainable—this would equate to a lifespan of 88 to 100 years. However, Cooper and his colleagues in 2022 estimated the length of this 46 year old individual at nearly {{cvt, 16, m, ft based on the 3D reconstruction which resulted in the complete vertebral column to be {{cvt, 11.1, m, ft long; the researchers claimed that this size estimate difference occurred due to the fact that Shimada and his colleagues extrapolated its size only based on the vertebral centra. Megalodon, like contemporaneous sharks, made use of nursery areas to birth their young in, specifically warm-water coastal environments with large amounts of food and protection from predators. Nursery sites were identified in the Gatún Formation of Panama, the

Calvert Formation The Calvert Formation is a geologic formation in Maryland, Virginia, and Delaware. It preserves fossils dating back to the early to middle Miocene epoch of the Neogene period. The formation is a destination for amateur fossil hunters as well as ...

of Maryland, Banco de Concepción in the Canary Islands,{{cite web, url=http://www.europapress.es/islas-canarias/noticia-identifican-canarias-fosiles-megalodon-tiburon-mas-grande-mayor-depredador-marino-existido-20130902152010.html, publisher=Europa Press Noticias SA, title=Identifican en Canarias fósiles de 'megalodón', el tiburón más grande que ha existido, trans-title=Identifying Canary fossils of 'megalodon', the largest shark that ever lived, language=es, year=2013, access-date=29 August 2017 and the

Bone Valley The Bone Valley is a region of central Florida, encompassing portions of present-day Hardee, Hillsborough, Manatee, and Polk counties, in which phosphate is mined for use in the production of agricultural fertilizer. Florida currently contains t ...

Formation of Florida. Given that all extant lamniform sharks give birth to live young, this is believed to have been true of megalodon also.{{cite journal, last1= Dulvy, first1=N. K., last2= Reynolds, first2=J. D., title= Evolutionary transitions among egg-laying, live-bearing and maternal inputs in sharks and rays, journal= Proceedings of the Royal Society B: Biological Sciences, volume= 264, issue= 1386, year=1997, pages= 1309–1315, doi= 10.1098/rspb.1997.0181, pmc=1688595, bibcode=1997RSPSB.264.1309D Infant megalodons were around {{convert, 3.5, m, ft, sp=us, sigfig=2 at their smallest,{{rp, 61 and the pups were vulnerable to predation by other shark species, such as the great hammerhead shark (''Sphyrna mokarran'') and the snaggletooth shark (''Hemipristis serra''). Their dietary preferences display an ontogenetic shift:{{rp, 65 Young megalodon commonly preyed on fish,{{Cite journal, last1=Pimiento, first1=Catalina, first2=Dana J., last2=Ehret, first3=Bruce J., last3=MacFadden , first4=Gordon, last4=Hubbell , title=Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama, journal=PLOS ONE, volume=5, issue=5, pages=e10552, year= 2010, pmid=20479893, pmc=2866656, doi=10.1371/journal.pone.0010552, editor1-last=Stepanova, editor1-first=Anna, bibcode = 2010PLoSO...510552P , doi-access=free sea turtles,{{cite journal, author1=Aguilera O. , author2=Augilera E. R. D. , title=Giant-toothed White Sharks and Wide-toothed Mako (Lamnidae) from the Venezuela Neogene: Their Role in the Caribbean, Shallow-water Fish Assemblage, journal=Caribbean Journal of Science, volume=40, issue=3, pages=362–368, year= 2004, url= https://www.researchgate.net/publication/228741311

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 m ...

s,{{rp, 129 and small cetaceans; mature megalodon moved to off-shore areas and consumed large cetaceans.{{rp, 74–75 An exceptional case in the fossil record suggests that juvenile megalodon may have occasionally attacked much larger balaenopterid whales. Three tooth marks apparently from a {{convert, 4, to, 7, m, ft, adj=on, sp=us long Pliocene shark were found on a rib from an ancestral blue or humpback whale that showed evidence of subsequent healing, which is suspected to have been inflicted by a juvenile megalodon.{{cite journal, last=Godfrey , first=Stephen, year=2004, title=The Ecphora, journal=The Newsletter of Calvert Marine Museum Fossil Club, volume=19, number=1, pages=1–13, url=http://calvertmarinemuseum.com/cmmfc/newsletter/CMMFC_Newsletter_2004-04.pdf, url-status=dead , archive-url=https://web.archive.org/web/20101210010152/http://calvertmarinemuseum.com/cmmfc/newsletter/CMMFC_Newsletter_2004-04.pdf , archive-date=10 December 2010{{cite journal, last=Kallal, first=R. J., author2=Godfrey, S. J. , author3=Ortner, D. J. , title=Bone Reactions on a Pliocene Cetacean Rib Indicate Short-Term Survival of Predation Event, journal=International Journal of Osteoarchaeology, volume=22, issue=3, pages=253–260, date=27 August 2010, doi=10.1002/oa.1199

Extinction

Climate change

The Earth experienced a number of changes during the time period megalodon existed which affected marine life. A cooling trend starting in the Oligocene 35 Mya ultimately led to glaciation at the poles. Geological events changed currents and precipitation; among these were the closure of the Central American Seaway and changes in the

Tethys Ocean The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

, contributing to the cooling of the oceans. The stalling of the Gulf Stream prevented nutrient-rich water from reaching major marine ecosystems, which may have negatively affected its food sources. The largest fluctuation of sea levels in the

Cenozoic era The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

occurred in the Plio-Pleistocene, between around 5 million to 12 thousand years ago, due to the expansion of glaciers at the poles, which negatively impacted coastal environments, and may have contributed to its extinction along with those of several other marine megafaunal species. These oceanographic changes, in particular the sea level drops, may have restricted many of the suitable shallow warm-water nursery sites for megalodon, hindering reproduction. Nursery areas are pivotal for the survival of many shark species, in part because they protect juveniles from predation.{{Cite news, last=Reilly, first=Michael, title=Prehistoric Shark Nursery Spawned Giants, publisher=Discovery News, date=29 September 2009, url=http://news.discovery.com/animals/megalodon-nursery-prehistoric-sharks.html, access-date=23 November 2013, archive-url= https://web.archive.org/web/20120310015215/http://news.discovery.com/animals/megalodon-nursery-prehistoric-sharks.html , archive-date= 10 March 2012 As its range did not apparently extend into colder waters, megalodon may not have been able to retain a significant amount of metabolic heat, so its range was restricted to shrinking warmer waters.{{cite web, url=http://www.elasmo-research.org/education/evolution/megalodon_extinction.htm, title=The Extinction of Megalodon, publisher=Biology of Sharks and Rays, access-date=31 August 2017 Fossil evidence confirms the absence of megalodon in regions around the world where water temperatures had significantly declined during the Pliocene.{{rp, 77 However, an analysis of the distribution of megalodon over time suggests that temperature change did not play a direct role in its extinction. Its distribution during the Miocene and Pliocene did not correlate with warming and cooling trends; while abundance and distribution declined during the Pliocene, megalodon did show a capacity to inhabit colder latitudes. It was found in locations with a mean temperature ranging from {{convert, 12, to, 27, C, F, with a total range of {{convert, 1, to, 33, C, F, indicating that the global extent of suitable habitat should not have been greatly affected by the temperature changes that occurred. This is consistent with evidence that it was a

mesotherm A mesotherm (from Greek μέσος ''mesos'' "intermediate" and ''thermē'' "heat") is a type of animal with a thermoregulatory strategy intermediate to cold-blooded ectotherms and warm-blooded endotherms. Definition Mesotherms have two basic c ...

Changing ecosystem

Marine mammals attained their greatest diversity during the Miocene,{{rp, 71 such as with baleen whales with over 20 recognized Miocene genera in comparison to only six extant genera. Such diversity presented an ideal setting to support a super-predator such as megalodon.{{rp, 75 By the end of the Miocene, many species of

mysticete Baleen whales (systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea (whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in their m ...

s had gone extinct; surviving species may have been faster swimmers and thus more elusive prey.{{rp, 46 Furthermore, after the closure of the Central American Seaway, tropical whales decreased in diversity and abundance.{{Cite journal, last=Allmon, first=Warren D., author2=Steven D. Emslie , author3=Douglas S. Jones , author4=Gary S. Morgan , title=Late Neogene Oceanographic Change along Florida's West Coast: Evidence and Mechanisms, journal=The Journal of Geology, volume= 104, issue=2, pages= 143–162, year=2006, doi= 10.1086/629811, bibcode=1996JG....104..143A, s2cid=128418299 The extinction of megalodon correlates with the decline of many small mysticete lineages, and it is possible that it was quite dependent on them as a food source. Additionally, a marine megafauna extinction during the Pliocene was discovered to have eliminated 36% of all large marine species including 55% of marine mammals, 35% of seabirds, 9% of sharks, and 43% of sea turtles. The extinction was selective for

endotherm An endotherm (from Greek ἔνδον ''endon'' "within" and θέρμη ''thermē'' "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions inst ...

s and mesotherms relative to

poikilotherm A poikilotherm () is an animal whose internal temperature varies considerably. Poikilotherms have to survive and adapt to environmental stress. One of the most important stressors is temperature change, which can lead to alterations in membrane ...

s, implying causation by a decreased food supply{{cite journal, first1=C., last1=Pimiento, first2=J. N., last2=Griffin, first3=C. F., last3=Clements, first4=D., last4=Silvestro, first5=S., last5=Varela, first6=M. D., last6=Uhen, first7=C., last7=Jaramillo, year=2017, title=The Pleistocene Marine Megafauna Extinction and its Impact on Functional Diversity, journal=Nature Ecology and Evolution, volume=1, issue=8, pages=1100–1106, doi=10.1038/s41559-017-0223-6, pmid=29046566, s2cid=3639394, url=https://cronfa.swan.ac.uk/Record/cronfa34515 and thus consistent with megalodon being mesothermic. Megalodon may have been too large to sustain itself on the declining marine food resources. The cooling of the oceans during the Pliocene might have restricted the access of megalodon to the polar regions, depriving it of the large whales which had migrated there. Competition from large odontocetes, such as macropredatory sperm whales which appeared in the Miocene, and a member of genus ''Orcinus'' (i.e., '' Orcinus citoniensis'') in the Pliocene, is assumed to have contributed to the decline and extinction of megalodon.{{rp, 46–47{{Cite journal, last1=McCormack, first1=Jeremy, last2=Griffiths, first2=Michael L., last3=Kim, first3=Sora L., last4=Shimada, first4=Kenshu, last5=Karnes, first5=Molly, last6=Maisch, first6=Harry, last7=Pederzani, first7=Sarah, last8=Bourgon , first8=Nicolas, last9=Jaouen, first9=Klervia, last10=Becker, first10=Martin A., last11=Jöns, first11=Niels, date=31 May 2022, title=Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes, journal=Nature Communications, language=en, volume=13, issue=1, pages=2980, doi=10.1038/s41467-022-30528-9, pmid=35641494, pmc=9156768 , bibcode=2022NatCo..13.2980M , s2cid=249235478, issn=2041-1723 But this assumption is disputed:{{cite journal, last1=Boessenecker, first1=R. W., last2=Ehret, first2=D. J., last3=Long, first3=D. J., last4= Churchill, first4= M., last5= Martin, first5= E., last6= Boessenecker, first6=S. J., title=The Early Pliocene extinction of the mega-toothed shark ''Otodus megalodon'': a view from the eastern North Pacific, journal= PeerJ, volume= 7, year= 2019, pages= e6088, doi= 10.7717/peerj.6088, pmid=30783558, pmc=6377595 The Orcininae emerged in Mid-Pliocene with ''O. citoniensis'' reported from the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58{{Cite journal, last1=Citron, first1=Sara, last2=Geisler, first2=Jonathan H., last3=Alberto, first3=Collareta, last4=Giovanni , first4=Bianucci, date=2022, title=Systematics, phylogeny and feeding behavior of the oldest killer whale: a reappraisal of Orcinus citoniensis (Capellini, 1883) from the Pliocene of Tuscany (Italy), journal=Bollettino della Società Paleontologica Italiana, volume=61, issue=2, pages=167–186, doi=10.4435/BSPI.2022.13 and similar forms reported from the Pliocene of England and South Africa, indicating the capacity of these dolphins to cope with increasingly prevalent cold water temperatures in high latitudes. These dolphins were assumed to have been macrophagous in some studies, but on closer inspection, these dolphins are not found to be macrophagous and fed on small fishes instead. On the other hand, gigantic macropredatory sperm whales such as '' Livyatan''-like forms are last reported from Australia and South Africa circa 5 million years ago.{{Cite web, url=http://www.australasianscience.com.au/article/issue-april-2016/huge-tooth-reveals-prehistoric-moby-dick-melbourne.html, title=Huge Tooth Reveals Prehistoric Moby Dick in Melbourne, publisher=Australasian Science Magazine, access-date=24 April 2016{{cite web, date=21 April 2016, publisher=The Sydney Morning Herald, title=Move over Moby Dick: Meet Melbourne's own mega whale, url=https://www.smh.com.au/technology/move-over-moby-dick-meet-melbournes-own-mega-whale-20160421-gobhl6.html{{Cite journal, last=Govender, first=R, title=Early Pliocene fossil cetaceans from Hondeklip Bay, Namaqualand, South Africa, journal=Historical Biology, year=2021, volume=33, issue=4, pages=574–593, doi=10.1080/08912963.2019.1650273, s2cid=202019648 Others, such as '' Hoplocetus'' and ''

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 ...

'' also occupied a niche similar to that of modern

killer whales The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus ''Orcinus'' and is recognizable by its black-and-white pat ...

but the last of these forms disappeared during the Pliocene.{{cite journal, last1= Hampe, first1= O., title= Middle/late Miocene hoplocetine sperm whale remains (Odontoceti: Physeteridae) of North Germany with an emended classification of the Hoplocetinae, journal= Fossil Record, volume= 9, issue= 1, year= 2006, pages= 61–86, doi= 10.1002/mmng.200600002, doi-access= free Members of genus ''Orcinus'' became large and macrophagous in the

. Paleontologist Robert Boessenecker and his colleagues rechecked the fossil record of megalodon for carbon dating errors and concluded that it disappeared circa 3.5 million years ago. Boessenecker and his colleagues further suggest that megalodon suffered range fragmentation due to climatic shifts, and competition with white sharks might have contributed to its decline and extinction. Competition with white sharks is assumed to be a factor in other studies as well,{{Cite journal, last1=Antunes, first1=Miguel Telles, first2=Ausenda Cáceres, last2=Balbino, title=The Great White Shark ''Carcharodon carcharias'' (Linne, 1758) in the Pliocene of Portugal and its Early Distribution in Eastern Atlantic, journal=Revista Española de Paleontología, volume=25, issue=1, pages=1–6, year=2010, url=http://recyt.fecyt.es/index.php/REP/article/viewFile/11488/7741 but this hypothesis warrants further testing.{{cite journal, last1=Kast, first1=Emma R., last2=Griffiths, first2=Michael L., last3=Kim, first3=Sora. L., last4=Rao, first4=Zixuan C., last5=Shimada, first5=Kensu, last6=Becker, first6=Martin A., last7=Maisch, first7=Harry M., last8=Eagle, first8=Robert A., last9=Clarke, first9=Chelesia A., last10=Neumann, first10=Allison N., last11=Karnes, first11=Molly E., last12=Lüdecke, first12=Tina, last13=Leichliter, first13=Jennifer N., last14=Martínez-García, first14=Alfredo, last15=Akhtar, first15=Alliya A., last16=Wang, first16=Xingchen T., last17=Haug, first17=Gerald H., last18=Sigman, first18=Daniel M., date=22 June 2022, title=Cenozoic megatooth sharks occupied extremely high trophic positions, journal=Science Advances, volume=8, issue=25, pages=eabl6529 , doi=10.1126/sciadv.abl6529, pmid=35731884 , pmc=9217088 , bibcode=2022SciA....8L6529K Multiple compounding environmental and ecological factors including climate change and thermal limitations, collapse of prey populations and resource competition with white sharks are believed to have contributed to decline and extinction of megalodon for now. The extinction of megalodon set the stage for further changes in marine communities. The average body size of baleen whales increased significantly after its disappearance, although possibly due to other, climate-related, causes.{{cite journal, last1= Slater, first1=G. J., last2= Goldbogen, first2=J. A., last3= Pyenson, first3=N. D., title= Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics, journal= Proceedings of the Royal Society B: Biological Sciences, volume= 284, issue= 1855, year= 2017, page= 20170546, doi= 10.1098/rspb.2017.0546, pmc=5454272, pmid=28539520 Conversely the increase in baleen whale size may have contributed to the extinction of megalodon, as they may have preferred to go after smaller whales; bite marks on large whale species may have come from scavenging sharks. Megalodon may have simply become coextinct with smaller whale species, such as '' Piscobalaena nana''.{{cite journal, first1=A., last1=Collareta, first2=O., last2=Lambert, first3=W., last3=Landini, first4=G., last4=Bianucci, year=2017, title=Did the giant extinct shark ''Carcharocles megalodon'' target small prey? Bite marks on marine mammal remains from the late Miocene of Peru, journal=Palaeogeography, Palaeoclimatology, Palaeoecology, volume=469, pages=84–91, doi=10.1016/j.palaeo.2017.01.001, bibcode=2017PPP...469...84C, hdl=10281/151854 The extinction of megalodon had a positive impact on other apex predators of the time, such as the great white shark, in some cases spreading to regions where megalodon became absent.{{Cite journal, last=Sylvain, first= Adnet, author2=A. C. Balbino , author3=M. T. Antunes, author4=J. M. Marín-Ferrer, title=New fossil teeth of the White Shark (''Carcharodon carcharias'') from the Early Pliocene of Spain. Implication for its paleoecology in the Mediterranean , journal=Neues Jahrbuch für Geologie und Paläontologie, volume= 256, issue=1, pages= 7–16, year=2010, doi= 10.1127/0077-7749/2009/0029

In popular culture

HMS challenger William Frederick Mitchell

Megalodon has been portrayed in many works of fiction, including films and novels, and continues to be a popular subject for fiction involving

sea monster Sea monsters are beings from folklore believed to dwell in the sea and often imagined to be of immense size. Marine monsters can take many forms, including sea dragons, sea serpents, or tentacled beasts. They can be slimy and scaly and are of ...

s.{{cite book, url={{google books, plainurl=yes, id=PHbeCwAAQBAJ, page=107, first=J. A., last=Weinstock, year=2014, title=The Ashgate Encyclopedia of Literary and Cinematic Monsters, publisher=

Routledge Routledge () is a British multinational publisher. It was founded in 1836 by George Routledge, and specialises in providing academic books, journals and online resources in the fields of the humanities, behavioural science, education, law ...

, pages=107–108, location=Farnham, United Kingdom, isbn=978-1-4094-2562-5, oclc=874390267 Reports of supposedly fresh megalodon teeth, such as those found by {{HMS, Challenger, 1858, 6 in 1873 which were dated in 1959 by the zoologist Wladimir Tschernezky to be around 11,000 to 24,000 years old, helped popularise claims of recent megalodon survival amongst

cryptozoologists Cryptozoology is a pseudoscience and subculture that searches for and studies unknown, legendary, or extinct animals whose present existence is disputed or unsubstantiated, particularly those popular in folklore, such as Bigfoot, the Loch Ness M ...

.{{Cite journal , last=Guimont , first=Edward , date=2021-10-05 , title=The Megalodon: A Monster of the New Mythology , url=https://journal.media-culture.org.au/index.php/mcjournal/article/view/2793 , journal=M/C Journal , language=en , volume=24 , issue=5 , doi=10.5204/mcj.2793 , s2cid=241813307 , issn=1441-2616 These claims are now discredited, and are probably teeth that were well-preserved by a thick mineral-crust

precipitate In an aqueous solution, precipitation is the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution. The solid formed is called the precipitate. In case of an inorganic chemical reaction leading ...

of manganese dioxide, and so had a lower decomposition rate and retained a white color during

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

ization. Fossil megalodon teeth can vary in color from off-white to dark browns and greys, and some fossil teeth may have been redeposited into a younger stratum. The claims that megalodon could remain elusive in the depths, similar to the

megamouth shark The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its d ...

which was discovered in 1976, are unlikely as the shark lived in warm coastal waters and probably could not survive in the cold and nutrient-poor deep sea environment. Contemporary fiction about megalodon surviving into modern times was pioneered by the 1997 novel '' Meg: A Novel of Deep Terror'' by Steve Alten and its subsequent sequels. Megalodon subsequently began to feature in films, such as the 2003 direct to video '' Shark Attack 3: Megalodon'', and later '' The Meg,'' a 2018 film based on the 1997 book which grossed over $500 million at the box office.

Animal Planet Animal Planet (stylized in all lowercase since 2018) is an American multinational pay television channel owned by the Warner Bros. Discovery Networks unit of Warner Bros. Discovery. First established on June 1, 1996, the network is primarily ...

pseudo-documentary A pseudo-documentary or fake documentary is a film or video production that takes the form or style of a documentary film but does not portray real events. Rather, scripted and fictional elements are used to tell the story. The pseudo-documentary, ...

'' Mermaids: The Body Found'' included an encounter 1.6 mya between a pod of

mermaid In folklore, a mermaid is an aquatic creature with the head and upper body of a female human and the tail of a fish. Mermaids appear in the folklore of many cultures worldwide, including Europe, Asia, and Africa. Mermaids are sometimes ass ...

s and a megalodon. Later, in August 2013, the Discovery Channel opened its annual

Shark Week Shark Week is an annual, week long TV programming block at the Discovery Channel, which features shark-based programming. Shark Week originally premiered on July 17, 1988. Featured annually, in July or early August, it was originally devoted to c ...

series with another film for television, '' Megalodon: The Monster Shark Lives'', a controversial

docufiction Docufiction (or docu-fiction) is the cinematographic combination of documentary and fiction, this term often meaning narrative film. It is a film genre which attempts to capture reality such as it is (as direct cinema or cinéma vérité) a ...

about the creature that presented alleged evidence in order to suggest that megalodon was still alive. This program received criticism for being completely fictional and for inadequately disclosing its fictional nature; for example, all of the supposed scientists depicted were paid actors, and there was no disclosure in the documentary itself that it was fictional. In a poll by Discovery, 73% of the viewers of the documentary thought that megalodon was not extinct. In 2014, Discovery re-aired ''The Monster Shark Lives'', along with a new one-hour program, ''Megalodon: The New Evidence'', and an additional fictionalized program entitled ''Shark of Darkness: Wrath of Submarine'', resulting in further backlash from media sources and the scientific community.{{cite news, url=http://op-talk.blogs.nytimes.com/2014/08/15/sorry-fans-discovery-has-jumped-the-shark-week, first=J., last=Flanagin, year=2014, title=Sorry, Fans. Discovery Has Jumped the Shark Week. , newspaper=New York Times, access-date=16 August 2014 Despite the criticism from scientists, ''Megalodon: The Monster Shark Lives'' was a huge ratings success, gaining 4.8 million viewers, the most for any Shark Week episode up to that point. Megalodon teeth are the state fossil of

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and ...

.{{Cite web, url=https://ncpedia.org/fossil-fossilized-teeth-megalodon, title=Fossil, Fossilized Teeth of the Megalodon Shark {{! NCpedia, website=ncpedia.org, access-date=17 October 2019

Notes

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References

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External links

{{Commons category, Otodus megalodon {{Wikispecies, Otodus (Megaselachus) megalodon, Megalodon
The rise of super predatory sharks

;Paleontological videos * {{YouTube, TUyWbW3yKFI, Paleontologist Mark Renz shows one of the largest megalodon teeth discovered * {{YouTube, 5N3EjR7_vks, Shark Week Special on megalodon with Pat McCarthy and John Babiarz with comments on its extinction. * {{YouTube, ciUDkIdptw0, Megalodon fossil teeth show evidence of 10-million-year-old shark nursery * {{YouTube, 85clp1k_sms, Expert view: information about megalodon (featuring expert Dana Ehret) * {{YouTube, e4p9EWuVxYQ, Lamniform sharks: 110 million years of ocean supremacy (featuring expert Mikael Siverson) * {{YouTube, suC2vQQz1Ak, The Rise and Fall of the Neogene Giant Sharks (featuring expert Bretton Kent) *{{cite web , first=Kallie , last=Moore , work= PBS Eons , date=19 December 2018 , title=Why Megalodon (Definitely) Went Extinct , url=https://www.youtube.com/watch?v=BTPcq2HczVY , archive-url=https://ghostarchive.org/varchive/youtube/20211114/BTPcq2HczVY, archive-date=14 November 2021 , url-status=live, via=

YouTube YouTube is a global online video sharing and social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google, and is the second mo ...

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