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114-530: Otodus megalodon ( / ˈ m ɛ ɡ əl ə d ɒ n / MEG -əl-ə-don ; meaning "big tooth"), commonly known as megalodon , is an extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Early Pliocene epochs. O. megalodon was formerly thought to be a member of the family Lamnidae and a close relative of

228-636: A dragon or other wild animals from biting the Moon. In the 19th century, during a lunar eclipse, the Chinese navy fired its artillery because of this belief. During the Zhou Dynasty ( c. 1046–256 BC) in the Book of Songs , the sight of a Red Moon engulfed in darkness was believed to foreshadow famine or disease. Certain lunar eclipses have been referred to as "blood moons" in popular articles but this

342-436: A period of flood that was later covered by terrestrial layers and uplifted by geologic activity. Swiss naturalist Louis Agassiz gave megalodon its scientific name in his seminal 1833-1843 work Recherches sur les poissons fossiles (Research on fossil fish). He named it Carcharias megalodon in an 1835 illustration of the holotype and additional teeth, congeneric with the modern sand tiger shark . The specific name

456-628: A 12th-century Maltese tradition to have belonged to serpents that Paul the Apostle turned to stone while shipwrecked there , and were given antivenom powers by the saint. Glossopetrae reappeared throughout Europe in late 13th to 16th century literature, ascribed with more supernatural properties that cured a wider variety of poisons . Use of megalodon teeth for this purpose became widespread among medieval and Renaissance nobility, who fashioned them into protective amulets and tableware to purportedly detoxify poisoned liquids or bodies that touched

570-465: A 20.3-meter (67 foot) monster would have topped off at 103 metric tons (114 tons). 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 individuals of different length by extrapolating from a vertebral centra based on the dimensions of the great white, a methodology also used for

684-408: A 3.85 m (12 ft 8 in) 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 61.56 t (67.86 short tons; 60.59 long tons) for a 16 meters (52 ft) long megalodon (higher than the previous estimates); a vertebral column specimen named IRSNB P 9893 (formerly IRSNB 3121), belonging to

798-735: A 46 year old individual from Belgium , 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 12.6 to 33.9 t (13.9 to 37.4 short tons; 12.4 to 33.4 long tons), and mature females may have been 27.4 to 59.4 t (30.2 to 65.5 short tons; 27.0 to 58.5 long tons), assuming that males could range in length from 10.5 to 14.3 meters (34 to 47 ft) and females 13.3 to 17 meters (44 to 56 ft). A 2015 study linking shark size and typical swimming speed estimated that megalodon would have typically swum at 18 kilometers per hour (11 mph)–assuming that its body mass

912-445: A Maltese megalodon tooth alongside a great white shark 's and noted their striking similarities. He argued that the former and its likenesses were not petrified serpent's tongues but actually the teeth of similar sharks that washed up on shore. Colonna supported this thesis through an experiment of burning glossopetrae samples, from which he observed carbon residue he interpreted as proving an organic origin. However, interpretation of

1026-430: A bite force of up to 108,500 to 182,200 newtons (24,390 to 40,960 lbf). 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 turtles . Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from

1140-444: 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 6-meter (20 ft) long female great white, which the authors considered the largest 'reasonably trustworthy' total length, produced an estimate of 16.8 meters (55 ft). However, based on the largest female great white reported, at 7.1 meters (23 ft), they estimated

1254-495: A lab, trade or industry that does not unambiguously describe a single chemical, such as copper sulfate , which may refer to either copper(I) sulfate or copper(II) sulfate. Sometimes common names are created by authorities on one particular subject, in an attempt to make it possible for members of the general public (including such interested parties as fishermen, farmers, etc.) to be able to refer to one particular species of organism without needing to be able to memorise or pronounce

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1368-405: A lack of lateral denticles , and a visible V-shaped neck (where the root meets the crown ). 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

1482-413: 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) × [UA maximum height ( mm )]-(0.22). Using this tooth height regression equation, the authors estimated a total length of 15.9 meters (52 ft) based on a tooth 16.8 centimeters (6.6 in) tall, which the authors considered

1596-424: A maximum estimate of 20.2 meters (66 ft). 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 1 centimeter (0.39 in) of root width, there are approximately 1.4 meters (4.6 ft) of shark length. Jeremiah pointed out that the jaw perimeter of a shark is directly proportional to its total length, with

1710-426: A mean relative cruising speed of 0.09 body lengths per second for a 16 meters (52 ft) 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 estimates. 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

1824-428: 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 ± 9 metres (30 ft)), casting doubt on some of

1938-504: A part of the Moon's surface facing Earth, the sun is partially blocked. The penumbra causes a subtle dimming of the lunar surface, which is only visible to the naked eye when the majority of the Moon's diameter has immersed into Earth's penumbra. A special type of penumbral eclipse is a total penumbral lunar eclipse , during which the entire Moon lies exclusively within Earth's penumbra. Total penumbral eclipses are rare, and when these occur,

2052-485: A particularly common name is used varies; some common names have a very local application, while others are virtually universal within a particular language. Some such names even apply across ranges of languages; the word for cat , for instance, is easily recognizable in most Germanic and many Romance languages . Many vernacular names, however, are restricted to a single country and colloquial names to local districts. Some languages also have more than one common name for

2166-404: 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

2280-468: A stockier version of the great white shark ( Carcharodon carcharias ), the basking shark ( 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 20.3 meters (67 ft), although the modal lengths are estimated at 10.5 meters (34 ft). Their teeth were thick and robust, built for grabbing prey and breaking bone, and their large jaws could exert

2394-690: A valued artifact amongst pre-Columbian cultures in the Americas for their large sizes and serrated blades, from which they were modified into projectile points , knives, jewelry, and funeral accessories. At least some, such as the Panamanian Sitio Conte societies, seemed to have used them primarily for ceremonial purposes. Mining of megalodon teeth by the Algonquin peoples in the Chesapeake Bay and their selective trade with

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2508-453: Is 18.4 centimeters (7.25 in), one of the largest known tooth specimens from the shark. In addition, a 2.7-by-3.4-meter (9 by 11 ft) megalodon jaw reconstruction developed by fossil hunter Vito Bertucci contains a tooth whose maximum height is reportedly over 18 centimeters (7 in). The most common fossils of megalodon are its teeth. Diagnostic characteristics include a triangular shape, robust structure, large size, fine serrations,

2622-507: Is a portmanteau of the Ancient Greek words μεγάλος ( megálos , meaning "big") and ὀδών ( odṓn , meaning "tooth"), combined meaning "big tooth". Agassiz referenced the name as early as 1832, but because specimens were not referenced they are not taxonomically recognized uses . Formal description of the species was published in an 1843 volume, where Agassiz revised the name to Carcharodon megalodon as its teeth were far too large for

2736-490: Is a global system that attempts to denote particular organisms or taxa uniquely and definitively , on the assumption that such organisms or taxa are well-defined and generally also have well-defined interrelationships; accordingly the ICZN has formal rules for biological nomenclature and convenes periodic international meetings to further that purpose. The form of scientific names for organisms, called binomial nomenclature ,

2850-424: Is about 1.03 km/s (2,300 mph), or a little more than its diameter per hour, so totality may last up to nearly 107 minutes. Nevertheless, the total time between the first and last contacts of the Moon's limb with Earth's shadow is much longer and could last up to 236 minutes. When the Moon's near side entirely passes into the Earth's umbral shadow, a total lunar eclipse occurs. Just prior to complete entry,

2964-404: Is because, as viewed from the Earth, the brightness of a lunar limb is generally greater than that of the rest of the surface due to reflections from the many surface irregularities within the limb: sunlight striking these irregularities is always reflected back in greater quantities than that striking more central parts, which is why the edges of full moons generally appear brighter than the rest of

3078-461: Is in these remarks from a book on marine fish: In scientific binomial nomenclature, names commonly are derived from classical or modern Latin or Greek or Latinised forms of vernacular words or coinages; such names generally are difficult for laymen to learn, remember, and pronounce and so, in such books as field guides, biologists commonly publish lists of coined common names. Many examples of such common names simply are attempts to translate

3192-425: Is not a scientifically recognized term. This term has been given two separate, but overlapping, meanings. The meaning usually relates to the reddish color a totally eclipsed Moon takes on to observers on Earth. As sunlight penetrates the atmosphere of Earth , the gaseous layer filters and refracts the rays in such a way that the green to violet wavelengths on the visible spectrum scatter more strongly than

3306-465: Is possible that large megalodon individuals had jaws spanning roughly 2 meters (6.6 ft) across. The teeth were also serrated , 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. In 2008, a team of scientists led by S. Wroe conducted an experiment to determine

3420-409: Is smaller. Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions. The symbol for a lunar eclipse (or any body in the shadow of another) is [REDACTED] (U+1F776 🝶). Earth's shadow can be divided into two distinctive parts: the umbra and penumbra . Earth totally occludes direct solar radiation within the umbra, the central region of

3534-459: Is superficially similar to the noun-adjective form of vernacular names or common names which were used by non-modern cultures. A collective name such as owl was made more precise by the addition of an adjective such as screech . Linnaeus himself published a flora of his homeland Sweden, Flora Svecica (1745), and in this, he recorded the Swedish common names, region by region, as well as

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3648-537: 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 . 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

3762-659: Is the Cape dikkop (or "gewone dikkop", not to mention the presumably much older Zulu name "umBangaqhwa"); Burhinus vermiculatus is the "water dikkop". The thick joints in question are not even, in fact, the birds' knees, but the intertarsal joints —in lay terms the ankles. Furthermore, not all species in the genus have "thick knees", so the thickness of the "knees" of some species is not of clearly descriptive significance. The family Burhinidae has members that have various common names even in English, including " stone curlews ", so

3876-463: Is the case with say, ginkgo , okapi , and ratel . Folk taxonomy , which is a classification of objects using common names, has no formal rules and need not be consistent or logical in its assignment of names, so that say, not all flies are called flies (for example Braulidae , the so-called "bee lice") and not every animal called a fly is indeed a fly (such as dragonflies and mayflies ). In contrast, scientific or biological nomenclature

3990-580: Is the largest living fish, with one large female reported with a precaudal length of 15 meters (49 ft) and an estimated total length of 18.8 meters (62 ft). 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. A C. megalodon about 16 meters long would have weighed about 48 metric tons (53 tons). A 17-meter (56-foot) C. megalodon would have weighed about 59 metric tons (65 tons), and

4104-457: Is the same effect that causes sunsets and sunrises to turn the sky a reddish color. An alternative way of conceiving this scenario is to realize that, as viewed from the Moon, the Sun would appear to be setting (or rising) behind Earth. The amount of refracted light depends on the amount of dust or clouds in the atmosphere; this also controls how much light is scattered. In general, the dustier

4218-573: The Adena culture in Ohio occurred as early as 430 BC . The earliest written account of megalodon teeth was by Pliny the Elder in an AD 73 volume of Historia Naturalis , who described them as resembling petrified human tongues that Roman folklorists believed to have fallen from the sky during lunar eclipses and called them glossopetrae ("tongue stones"). The purported tongues were later thought in

4332-482: The Gatún Formation of Panama, one upper lateral tooth was used by other researchers to obtain a total length estimate of 17.9 meters (59 ft) 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

4446-635: The Paleocene through the Miocene epochs, 60 to 13 Mya. The genus Otodus is ultimately derived from Cretolamna , a shark from the Cretaceous 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 ,

4560-442: The basking shark ( 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 ). 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

4674-454: The full moon phase, when the Moon's orbital plane is closest to the plane of the Earth's orbit . This can occur only when the Sun , Earth, and Moon are exactly or very closely aligned (in syzygy ) with Earth between the other two, which can happen only on the night of a full moon when the Moon is near either lunar node . The type and length of a lunar eclipse depend on the Moon's proximity to

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4788-513: The great white shark ( Carcharodon carcharias ), but has been reclassified into the extinct family Otodontidae , 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, 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

4902-411: The modal total body length at 10.5 meters (34 ft), calculated from 544 megalodon teeth, found throughout geological time and geography, including juveniles and adults ranging from 2.2 to 17.9 metres (7.2 to 58.7 ft) in total length. In comparison, large great white sharks are generally around 6 meters (20 ft) in length, with a few contentious reports suggesting larger sizes. The whale shark

5016-588: The principle of priority . While the earliest megalodon remains have been reported from the Late Oligocene , around 28 million years ago (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 , about 2.6 Mya; claims of Pleistocene megalodon teeth, younger than 2.6 million years old, are considered unreliable. A 2019 assessment moves

5130-405: 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 since considered a junior synonym of Carcharocles . The genus Palaeocarcharodon was erected alongside Procarcharodon to represent the beginning of

5244-466: 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 16 meters (52 ft) long megalodon would have had a 4.65 m (15.3 ft) long head, 1.41 m (4 ft 8 in) tall gill slits, a 1.62 m (5 ft 4 in) tall dorsal fin, 3.08 m (10 ft 1 in) long pectoral fins, and

5358-586: The Earth was round and used the shadow from the lunar eclipse as evidence. Some Hindus believe in the importance of bathing in the Ganges River following an eclipse because it will help to achieve salvation . Similarly to the Mayans, the Incans believed that lunar eclipses occurred when a jaguar ate the Moon, which is why a blood moon looks red. The Incans also believed that once the jaguar finished eating

5472-477: The Earth's umbra, both it and the Sun can be observed in the sky because atmospheric refraction causes each body to appear higher (i.e., more central) in the sky than its true geometric planetary position. The timing of total lunar eclipses is determined by what are known as its "contacts" (moments of contact with Earth's shadow): The following scale (the Danjon scale ) was devised by André Danjon for rating

5586-756: The Hebrew Language publish from time to time short dictionaries of common name in Hebrew for species that occur in Israel or surrounding countries e.g. for Reptilia in 1938, Osteichthyes in 2012, and Odonata in 2015. Lunar eclipse A lunar eclipse is an astronomical event that occurs when the Moon moves into the Earth's shadow , causing the Moon to be darkened. Such an alignment occurs during an eclipse season , approximately every six months, during

5700-465: The Moon would be completely dark during the eclipse. The reddish coloration arises because sunlight reaching the Moon must pass through a long and dense layer of Earth's atmosphere, where it is scattered . Shorter wavelengths are more likely to be scattered by the air molecules and small particles ; thus, the longer wavelengths predominate by the time the light rays have penetrated the atmosphere. Human vision perceives this resulting light as red . This

5814-463: The Moon, it could come down and devour all the animals on Earth, so they would take spears and shout at the Moon to keep it away. The ancient Mesopotamians believed that a lunar eclipse was when the Moon was being attacked by seven demons. This attack was more than just one on the Moon, however, for the Mesopotamians linked what happened in the sky with what happened on the land, and because

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5928-710: The SSAR switched to an online version with a searchable database. Standardized names for the amphibians and reptiles of Mexico in Spanish and English were first published in 1994, with a revised and updated list published in 2008. A set of guidelines for the creation of English names for birds was published in The Auk in 1978. It gave rise to Birds of the World: Recommended English Names and its Spanish and French companions. The Academy of

6042-534: The Secretariat for the AFNC. SSA is an accredited Standards Australia (Australia's peak non-government standards development organisation) Standards Development The Entomological Society of America maintains a database of official common names of insects, and proposals for new entries must be submitted and reviewed by a formal committee before being added to the listing. Efforts to standardize English names for

6156-505: The amphibians and reptiles of North America (north of Mexico) began in the mid-1950s. The dynamic nature of taxonomy necessitates periodical updates and changes in the nomenclature of both scientific and common names. The Society for the Study of Amphibians and Reptiles (SSAR) published an updated list in 1978, largely following the previous established examples, and subsequently published eight revised editions ending in 2017. More recently

6270-485: The atmosphere, the more that other wavelengths of light will be removed (compared to red light), leaving the resulting light a deeper red color. This causes the resulting coppery-red hue of the Moon to vary from one eclipse to the next. Volcanoes are notable for expelling large quantities of dust into the atmosphere, and a large eruption shortly before an eclipse can have a large effect on the resulting color. Several cultures have myths related to lunar eclipses or allude to

6384-515: The author introduced into it so many new English names, that are to be found in no dictionary, and that do not preclude the necessity of learning with what Latin names they are synonymous. A tolerable idea may be given of the danger of too great a multiplicity of vulgar names, by imagining what geography would be, or, for instance, the Post-office administration, supposing every town had a totally different name in every language. Various bodies and

6498-493: The authors of many technical and semi-technical books do not simply adapt existing common names for various organisms; they try to coin (and put into common use) comprehensive, useful, authoritative, and standardised lists of new names. The purpose typically is: Other attempts to reconcile differences between widely separated regions, traditions, and languages, by arbitrarily imposing nomenclature, often reflect narrow perspectives and have unfortunate outcomes. For example, members of

6612-402: 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 14.2–20.3 meters (47–67 ft). A 2015 study estimated

6726-405: The bite force of the great white shark, using a 2.5-meter (8.2 ft) 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 108,514 to 182,201 newtons (24,395 to 40,960 lbf) in a posterior bite, compared to the 18,216 newtons (4,095 lbf) bite force for

6840-556: 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 13 meters (43 ft). 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 24 to 25 meters (79 to 82 ft) in total length. In 1996, shark researchers Michael D. Gottfried, Leonard Compagno , and S. Curtis Bowman proposed

6954-416: The brightness of the lunar limb—the curved edge of the Moon still being hit by direct sunlight—will cause the rest of the Moon to appear comparatively dim. The moment the Moon enters a complete eclipse, the entire surface will become more or less uniformly bright, being able to reveal stars surrounding it. Later, as the Moon's opposite limb is struck by sunlight, the overall disk will again become obscured. This

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7068-438: 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. Common name In chemistry , IUPAC defines a common name as one that, although it unambiguously defines a chemical, does not follow the current systematic naming convention, such as acetone , systematically 2-propanone , while a vernacular name describes one used in

7182-419: The centre of Earth's shadow, contacting the antisolar point . This type of lunar eclipse is relatively rare . The relative distance of the Moon from Earth at the time of an eclipse can affect the eclipse's duration. In particular, when the Moon is near apogee , the farthest point from Earth in its orbit , its orbital speed is the slowest. The diameter of Earth's umbra does not decrease appreciably within

7296-474: The changes in the Moon's orbital distance. Thus, the concurrence of a totally eclipsed Moon near apogee will lengthen the duration of totality. A selenelion or selenehelion , also called a horizontal eclipse , occurs where and when both the Sun and an eclipsed Moon can be observed at the same time. The event can only be observed just before sunset or just after sunrise , when both bodies will appear just above opposite horizons at nearly opposite points in

7410-408: The choice of the name "thick-knees" is not easy to defend but is a clear illustration of the hazards of the facile coinage of terminology. For collective nouns for various subjects, see a list of collective nouns (e.g. a flock of sheep, pack of wolves). Some organizations have created official lists of common names, or guidelines for creating common names, hoping to standardize

7524-590: The conclusions of previous studies using that method. Using the largest tooth available to the authors, GHC 6, with a crown width of 13.3 centimeters (5.2 in), they estimated a maximum body length of approximately 20 meters (66 ft), with a range of error of approximately ± 3.5 metres (11 ft). 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

7638-481: The disappearance of the lateral 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

7752-433: The drag-reducing adaptations are toward the tail-end of the animal. One associated set of megalodon remains was found with placoid scales, which are 0.3 to 0.8 millimetres (0.012 to 0.031 in) in maximum width, and have broadly spaced keels. 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

7866-424: The evolution of regional endothermy ( mesothermy ) which would have increased its metabolic rate and swimming speed. The otodontid sharks have been considered to have been ectotherms , 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 regional endotherms, implying some metabolic correlations with

7980-415: The extinction date back to earlier in the Pliocene, 3.6 Mya. Megalodon is 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 believe that this is due to convergent evolution . In this model,

8094-407: The former genus and more alike to the great white shark. He also erroneously identified several megalodon teeth as belonging to additional species eventually named Carcharodon rectidens , Carcharodon subauriculatus , Carcharodon productus , and Carcharodon polygurus . Because Carcharodon megalodon appeared first in the 1835 illustration, the remaining names are considered junior synonyms under

8208-449: 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

8322-441: The fossil record by teeth, vertebral centra , and coprolites . As with all sharks, the skeleton of megalodon was formed of cartilage rather than bone ; 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 ,

8436-522: The genus Burhinus occur in Australia, Southern Africa, Eurasia, and South America. A recent trend in field manuals and bird lists is to use the name " thick-knee " for members of the genus. This, in spite of the fact that the majority of the species occur in non-English-speaking regions and have various common names, not always English. For example, "Dikkop" is the centuries-old South African vernacular name for their two local species: Burhinus capensis

8550-561: 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 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

8664-405: The great white shark are more closely related, argue that the differences between their dentition are minute and obscure. The genus Carcharocles 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

8778-437: 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 sharks ( Isurus spp.), with a common ancestor around 4 Mya. Proponents of the former model, wherein megalodon and

8892-455: The great white shark. Modified from Shimada et al. (2016), Ehret et al., (2009), and the findings of Siversson et al. (2015). Kenolamna gunsoni Cretalamna appendiculata Cretalamna aschersoni Megalolamna paradoxodon [REDACTED] Otodus obliquus Otodus megalodon [REDACTED] Isurus oxyrinchus [REDACTED] Carcharodon carcharias [REDACTED] One interpretation on how megalodon appeared

9006-400: The head of a great white caught in 1666. His 1667 report depicted engravings of a shark's head and megalodon teeth that became especially iconic. However, the illustrated head was not actually the head that Steensen dissected, nor were the fossil teeth illustrated by him. Both engravings were originally commissioned in the 1590s by Papal physician Michele Mercati , who also had in possession

9120-605: The head of a great white, for his book Metallotheca . The work remained unpublished in Steensen's time due to Mercati's premature death, and the former reused the two illustrations per suggestion by Carlo Roberto Dati , who thought a depiction of the actual dissected shark was unsuitable for readers. Steensen also stood out in pioneering a stratigraphic explanation for how similar stones appeared further inland. He observed that rock layers bearing megalodon teeth contained marine sediments and hypothesized that these layers correlated to

9234-506: The jaw of megalodon was made by Bashford Dean 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 30 meters (98 ft) 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

9348-424: The king of Mesopotamia represented the land, the seven demons were thought to be also attacking the king. In order to prevent this attack on the king, the Mesopotamians made someone pretend to be the king so they would be attacked instead of the true king. After the lunar eclipse was over, the substitute king was made to disappear (possibly by poisoning ). In some Chinese cultures, people would ring bells to prevent

9462-595: 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 14.2 meters (47 ft). The tooth with the tallest total height, FMNH PF 11306, was reported at 16.8 centimeters (6.6 in). However, Shimada remeasured the tooth and found it actually to measure 16.2 centimeters (6.4 in). Using the total height tooth regression equation proposed by Gottfried and colleagues produced an estimate of 15.3 meters (50 ft). In 2021, Victor J. Perez, Ronny M. Leder, and Teddy Badaut proposed

9576-436: The largest confirmed great white shark, and 7,495 newtons (1,685 lbf) for the placoderm fish Dunkleosteus . 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

9690-430: 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 , which lived from

9804-584: The lunar eclipse as being a good or bad omen . The Egyptians saw the eclipse as a sow swallowing the Moon for a short time; other cultures view the eclipse as the Moon being swallowed by other animals, such as a jaguar in Mayan tradition, or a mythical three-legged toad known as Chan Chu in China . Some societies thought it was a demon swallowing the Moon, and that they could chase it away by throwing stones and curses at it. The Ancient Greeks correctly believed

9918-472: The lunar node. When the Moon is totally eclipsed by the Earth (a "deep eclipse"), it takes on a reddish color that is caused by the planet when it completely blocks direct sunlight from reaching the Moon's surface, as the only light that is reflected from the lunar surface is what has been refracted by the Earth's atmosphere . This light appears reddish due to the Rayleigh scattering of blue light,

10032-411: The lunar surface. This is similar to the effect of velvet fabric over a convex curved surface, which, to an observer, will appear darkest at the center of the curve. It will be true of any planetary body with little or no atmosphere and an irregular cratered surface (e.g., Mercury) when viewed opposite the Sun. Central lunar eclipse is a total lunar eclipse during which the Moon passes near and through

10146-711: The modern (now binding) International Code of Nomenclature for algae, fungi, and plants contains the following: Art. 68. Every friend of science ought to be opposed to the introduction into a modern language of names of plants that are not already there unless they are derived from a Latin botanical name that has undergone but a slight alteration. ... ought the fabrication of names termed vulgar names, totally different from Latin ones, to be proscribed. The public to whom they are addressed derives no advantage from them because they are novelties. Lindley's work, The Vegetable Kingdom, would have been better relished in England had not

10260-463: The onset of the ice ages , 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. Megalodon teeth have been excavated and used since ancient times. They were

10374-414: The overall darkness of lunar eclipses: There is often confusion between a solar eclipse and a lunar eclipse. While both involve interactions between the Sun, Earth, and the Moon, they are very different in their interactions. The Moon does not completely darken as it passes through the umbra because of the refraction of sunlight by Earth's atmosphere into the shadow cone; if Earth had no atmosphere,

10488-450: The portion of the Moon closest to the umbra may appear slightly darker than the rest of the lunar disk. When the Moon's near side penetrates partially into the Earth's umbra, it is known as a partial lunar eclipse, while a total lunar eclipse occurs when the entire Moon enters the Earth's umbra. During this event, one part of the Moon is in the Earth's umbra, while the other part is in the Earth's penumbra. The Moon's average orbital speed

10602-420: 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 15 meters (49 ft). Among several specimens found in

10716-440: The red, thus giving the Moon a reddish cast. This is possible because the rays from the Sun are able to wrap around the Earth and reflect off the Moon. At least two lunar eclipses and as many as five occur every year, although total lunar eclipses are significantly less common than partial lunar eclipses. If the date and time of an eclipse is known, the occurrences of upcoming eclipses are predictable using an eclipse cycle , like

10830-488: The same animal. For example, in Irish, there are many terms that are considered outdated but still well-known for their somewhat humorous and poetic descriptions of animals. w/ literal translations of the poetic terms Common names are used in the writings of both professionals and laymen . Lay people sometimes object to the use of scientific names over common names, but the use of scientific names can be defended, as it

10944-398: The same reason sunrises and sunsets are more orange than during the day. Unlike a solar eclipse , which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. A total lunar eclipse can last up to nearly two hours (while a total solar eclipse lasts only a few minutes at any given place) because the Moon's shadow

11058-402: The scientific name into English or some other vernacular. Such translation may be confusing in itself, or confusingly inaccurate, for example, gratiosus does not mean "gracile" and gracilis does not mean "graceful". The practice of coining common names has long been discouraged; de Candolle's Laws of Botanical Nomenclature , 1868, the non-binding recommendations that form the basis of

11172-555: The scientific name. Creating an "official" list of common names can also be an attempt to standardize the use of common names, which can sometimes vary a great deal between one part of a country and another, as well as between one country and another country, even where the same language is spoken in both places. A common name intrinsically plays a part in a classification of objects, typically an incomplete and informal classification, in which some names are degenerate examples in that they are unique and lack reference to any other name, as

11286-579: The scientific names. The Swedish common names were all binomials (e.g. plant no. 84 Råg-losta and plant no. 85 Ren-losta); the vernacular binomial system thus preceded his scientific binomial system. Linnaean authority William T. Stearn said: By the introduction of his binomial system of nomenclature, Linnaeus gave plants and animals an essentially Latin nomenclature like vernacular nomenclature in style but linked to published, and hence relatively stable and verifiable, scientific concepts and thus suitable for international use. The geographic range over which

11400-412: The shadow. However, since the Sun's diameter appears to be about one-quarter of Earth's in the lunar sky , the planet only partially blocks direct sunlight within the penumbra, the outer portion of the shadow. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into the Earth's penumbra. No part of the moon is in the Earth's umbra during this event, meaning that on all or

11514-453: The shark may actually belong in the genus Otodus , making it Otodus megalodon . A 1974 study on Paleogene sharks by Henri Cappetta erected the subgenus Megaselachus , classifying the shark as Otodus ( Megaselachus ) megalodon , along with O. (M.) chubutensis . A 2006 review of Chondrichthyes elevated Megaselachus to genus, and classified the sharks as Megaselachus megalodon and M. chubutensis . The discovery of fossils assigned to

11628-405: The sky. A selenelion occurs during every total lunar eclipse—it is an experience of the observer , not a planetary event separate from the lunar eclipse itself. Typically, observers on Earth located on high mountain ridges undergoing false sunrise or false sunset at the same moment of a total lunar eclipse will be able to experience it. Although during selenelion the Moon is completely within

11742-418: 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 claspers , like modern cartilaginous fish). The first attempt to reconstruct

11856-411: 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 ( Orcinus ). As the shark preferred warmer waters, it is thought that oceanic cooling associated with

11970-441: The stones as shark's teeth remained widely unaccepted. This was in part due the inability to explain how some of them are found far from the sea. The shark tooth argument was academically raised again during the late 17th century by English scientists Robert Hooke , John Ray , and Danish naturalist Niels Steensen (Latinized Nicholas Steno ). Steensen's argument in particular is most recognized as inferred from his dissection of

12084-430: The stones. By the 16th century, teeth were directly consumed as ingredients of European-made Goa stones . The true nature of the glossopetrae as shark's teeth was held by some since at least 1554, when cosmographer André Thevet described it as hearsay, although he did not believe it. The earliest scientific argument for this view was made by Italian naturalist Fabio Colonna , who in 1616 published an illustration of

12198-434: 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

12312-426: 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 180 millimeters (7.1 in) 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

12426-832: The use of common names. For example, the Australian Fish Names List or AFNS was compiled through a process involving work by taxonomic and seafood industry experts, drafted using the CAAB (Codes for Australian Aquatic Biota) taxon management system of the CSIRO , and including input through public and industry consultations by the Australian Fish Names Committee (AFNC). The AFNS has been an official Australian Standard since July 2007 and has existed in draft form (The Australian Fish Names List) since 2001. Seafood Services Australia (SSA) serve as

12540-552: 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 12 centimeters (4.7 in), which yielded 16.5 meters (54 ft) 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

12654-696: Was discovered in Saitama, Japan . 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 (USNM). Based on these discoveries, an artificial dental formula was put together for megalodon in 1996. The dental formula of megalodon is: 2.1.7.4 3.0.8.4 . As evident from

12768-411: 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. Megalodon is represented in

12882-426: 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 whale shark ( Rhincodon typus ) or

12996-455: Was typically 48 t (53 short tons; 47 long tons)–which is consistent with other aquatic creatures of its size, such as the fin whale ( Balaenoptera physalus ) which typically cruises at speeds of 14.5 to 21.5 km/h (9.0 to 13.4 mph). In 2022, Cooper and his colleagues converted this calculation into relative cruising speed (body lengths per second), resulting in a mean absolute cruising speed of 5 kilometers per hour (3.1 mph) and

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