Megalodon 529138 226056154 2008-07-16T17:06:39Z 67.212.99.82 The novel Jaws is not about a megladon, but rather a large great white. {{otheruses}} {{Taxobox | name = ''Megalodon'' | fossil_range = [[Miocene]] - [[Pleistocene]] | image = Carcharodon megalodon P1060082.jpg | image_width=250px | image_caption = ''Megalodon'' jaws | status = EX | status_system = iucn2.3 | regnum = [[Animal]]ia | phylum = [[Chordate|Chordata]] | subphylum = [[Vertebrata]] | classis = [[Chondrichthyes]] | subclassis = [[Elasmobranchii]] | ordo = [[Lamniformes]] | familia = [[Lamnidae]] | genus = ''[[Carcharodon]]'' | species = '''''C. megalodon''''' | binomial = ''Carcharodon megalodon'' | binomial_authority = [[Louis Agassiz|Agassiz]], 1843 | synonyms = * ''Procarcharodon megalodon'' <small>Casier, 1960</small> }} The '''''megalodon''''' ({{pronEng|ˡmɛ.gə.ləˌdɒn}} or ''MEG''-a-la-don; meaning "big tooth" or [[Greek language|in Greek as]] μέγας 'οδόντος) was a giant [[shark]] that lived in [[prehistoric]] times, between about 18 million to 1.5 million years ago{{cref|a}} and was the [[apex predator]] of its time. It is the largest [[carnivor]]ous [[fish]] known to have existed,<ref name="H">{{Citebook|last=Renz|first=Mark|title=Megalodon: Hunting the Hunter|publisher=PaleoPress|date=2002|isbn=0-9719477-0-8}}</ref> and quite possibly the largest shark to have ever lived. It is believed that the average size of the megalodon was between {{convert|12|m|ft|0|lk=on}} and {{convert|18|m|ft|0|lk=on}}. This species is a member of the [[lamnidae]] family but its classification is in dispute and a new [[genus]] has been proposed. [[Fossil]] evidence has revealed that megalodon fed upon large [[animal]]s, including the early [[whale]]s.<ref name="E">{{Citation|last=Roesch |first=Ben|title=The Cryptozoology Review: A Critical Evaluation of the Supposed Contemporary Existence of Carcharodon Megalodon|url=http://www.ncf.carleton.ca/~bz050/megalodon.html|year=1998}}</ref> Some [[cryptozoologist]]s argue that this shark might still be alive today, probably living in deep waters, and often cite the examples of [[coelacanth]] and [[megamouth shark]] to support their claims.<ref name="E" /> However, such beliefs have earned no credibility in the mainstream [[scientific community]]. == Taxonomy == The [[Switzerland|Swiss]] [[naturalist]], [[Louis Agassiz]], gave this shark its scientific name, ''Carcharodon megalodon'' in 1835,<ref name="A">{{Citepaper|author=Kevin G.N, Charles N.C, Gregory A.W|title=Tracing the ancestry of the GREAT WHITE SHARK|date=2006|url=http://www.biology.duke.edu/wraylab/papers/Nyberg&al_2006.pdf|format=[[PDF]]|accessdate=2007-12-25}}</ref> in his research work ''Recherches sur les poissons fossiles'' (''Research on [[fish]] fossils''), which he completed in 1843. Due to the dental similarities of the [[teeth]] of the [[great white shark]], ''Carcharodon carcharias'', and megalodon, Agassiz proposed ''Carcharodon'' as the genus.<ref name="A" /> In-short, this shark is termed ''C. megalodon'' by shark researchers. However, it is often dubbed the "mega-tooth shark" or "giant white shark." === Classification dispute === {{userboxtop|align=right|bordercolor=lightgray|toptext=[[Cladistics#Cladograms|Cladogram]] of the ''"hastalis hypothesis"'' highlighting the position of ''C. megalodon''}} <br/><u><center>'''Muizon ''et al.'' 1985'''<ref name="A" /></center></u> {{clade| style=font-size:80%;line-height:80% |label1=[[Lamniformes]]&nbsp; |1={{clade |label1=<font color="white">void</font> |1={{clade |label1=<font color="white">void</font> |1={{clade |label1=<font color="white">void</font> |1=''I. hastalis'' |2={{clade |label1=&nbsp;<font color="white">void</font>&nbsp; |1=''Sacaco Sp.'' |2=''C. carcharias''}} }} |label2=<font color="white">void</font> |2='''''C. megalodon''''' }} }} }} <small>*<u>Note</u>: The '''hastalis hypothesis''' shows that ''C. carcharias'' is more closely related to ''I. hastalis'' than ''C. megalodon''.<ref name="A" /></small> {{userboxbottom}} There is a major disagreement among [[scientist]]s as to how ''C. megalodon'' should be classified.<ref name="H" /><ref name="E" /> The controversy is that whether ''C. megalodon'' is a close relative of the extant great white shark or whether the two species are distant relatives. The trend among shark researchers is to dismiss the statement that ''C. megalodon'' is a close relative of the great white shark, in favor of citing [[convergent evolution]] as the reason for the dental similarity. ==== ''Megalodon'' within ''Carcharodon'' ==== The traditional view is that ''C. megalodon'' should be classified within the genus ''Carcharodon'' along with the great white shark. The ''Carcharodon'' proponents suggest that ''C. megalodon'' and ''C. carcharias'' share a [[common ancestor]] known as ''Carcharodon orientalis''.<ref name="H" /><ref name="A" /><ref name="G">{{Citation|last1=Klimley|first1=Peter|last2=Ainley|first2=David|title=Great White Sharks: The Biology of Carcharodon carcharias|publisher=Academic Press|date=1996|isbn=0124150314}}</ref> ==== ''Megalodon'' within ''Carcharocles'' ==== Around 1923, the genus, '''''Carcharocles''''', was proposed by two shark researchers, D. S. Jordan and H. Hannibal, to classify a very similar shark ''C. auriculatus''. Many [[marine biologist]]s and [[paleontologist]]s are now favoring the ''Carcharocles'' genus for ''C. megalodon''.<ref name="H" /><ref name="E" /><ref name="A" /><ref name="C">{{Citeweb|last=Andres|first=Lutz|title=C. megalodon - Megatooth Shark, Carcharodon versus Carcharocles|url=http://www.fossilguy.com/topics/megshark/megshark.htm|year=2002|accessdate=2008-01-16}}</ref><ref name="J">{{Citeweb|last=Bowling|first=Stuart|title=C. Megalodon|url=http://greatwhite.org/frame_meg.htm|year=1997}}</ref> One reason for this shift is that the teeth of ''C. megalodon'' are also similar to the teeth of some sharks that belong to ''Carcharocles'' lineage. The ''Carcharocles'' proponents suggest that the direct ancestor of the sharks belonging to the ''Carcharocles'' genus, is an ancient shark called ''[[Otodus obliquus]]'', which lived during the [[Paleocene]] and [[Eocene]] epochs.<ref name="H" /><ref name="C" /> According to Carcharocles proponents, ''Otodus obliquus'' evolved in to ''Carcharocles aksuaticus'',<ref name="H" /><ref name="C" /> which evolved in to ''Carcharocles auriculatus'',<ref name="H" /><ref name="C" /> which evolved into ''Carcharocles augustidens'',<ref name="H" /><ref name="C" /> which evolved into ''Carcharocles chubutensis'',<ref name="H" /><ref name="C" /> which eventually evolved into megalodon.<ref name="H" /><ref name="C" /> Hence, the immediate ancestor of ''C. megalodon'' is ''Carcharocles chubutensis'',<ref name="H" /><ref name="C" /> because it serves as the missing link between ''Carcharocles augustidens'' and ''C. megalodon'' and it bridges the loss of the "lateral cusps" that characterize ''C. megalodon''.<ref name="H" /><ref name="C" /> ''Carcharocles '' proponents also point out that the great white shark is more closely related to an ancient shark ''Isurus hastalis'', the "broad tooth [[Isurus|mako]]," than ''C. megalodon''. This suggestion is given credence by many scientists due to some convincing evidence.<ref name="A" /><ref name="J" /><ref name="O">{{Citeweb|last=Alter|first=Steven|title=Origin of the Modern Great White Shark |url=http://www.megalodonteeth.com/articles/article2.html|year=2001|accessdate=2008-01-13}}</ref> One reason is that the teeth of ''I. hastalis'' and ''C. carcharias'' are remarkably similar in shape, differing only in that the former lack the characteristic serrations of the latter.<ref name="H" /><ref name="A" /><ref name="O" /> == Anatomy and appearance == [[Image:Megalodon.jpg|thumb|Megalodon tooth from the [[Miocene]]. Dimensions: 13 cm straight, 18 cm in diagonal.]] ''C. megalodon'' is known primarily from fossil teeth and a few fossilized [[vertebra|vertebral centra]].<ref name="D" >{{Citenews|last=Bruner|first=John|title=The Megatooth shark|year=1997|publisher=FLMNH|url=http://www.flmnh.ufl.edu/fish/sharks/InNews/megatoothshark.htm|accessdate=2008-01-16}}</ref> As with all other sharks, the megalodon [[skeleton]] was formed of [[cartilage]] and not [[bone]], resulting in a poor skeletal fossil record.<ref name="E" /> The teeth are in many ways similar to great white shark teeth but are much larger and can measure up to more than 18 [[centimetre|cm]] in slant.<ref name="H" /> Nevertheless, it is extrapolations from the shape and size of the teeth of ''C. megalodon'' when compared with related modern sharks and studies of their physical characteristics, that provide us with our conceptions about what this ancient super-[[predator]] might have looked like in life. Thus far, the great white shark has been considered the favored model for the basis for the reconstruction of ''C. megalodon''.<ref name="G" /><ref name="D" /> === Size estimation === [[Image:Megalodon scale1.png|thumb|left|Megalodon with the great white shark and a human for scale.]] Estimating the maximum size of ''C. megalodon'' is a highly controversial subject. An early [[jaw]] reconstruction of this shark, developed by Professor [[Bashford Dean]] in 1909, indicates a length of more than {{convert|25|m|ft|0|lk=on}}, but that jaw reconstruction is now considered to be inaccurate.<ref name="D" /> One reason is that the teeth used as posteriors in this jaw reconstruction were not true posterior teeth. However, several scientists have tried to solve this issue in later years and some examples are mentioned below. In 1973, the ichthyiologist John E. Randall suggested a method to measure the size of the large sharks.<ref name="W">{{cite journal|last=Randall|first=John|title=Size of the Great White Shark (Carcharodon)|journal=Science Magazine|pages=169–170|date= July 1973}}</ref> According to Randall, the enamel height of the largest tooth in the upper jaw of the shark can be used to determine its total length. He concluded that ''C. megalodon'' could grow to {{convert|13|m|ft|0|lk=on}}.<ref name="W" /> However, in 1996, three shark experts, Michael D. Gottfried, [[Leonard Compagno|Leonard J. V. Compagno]] and S. Curtis Bowman, questioned the reliability of Randall's method. According to them, shark's tooth enamel height does not necessarily increase in proportion with the animal's total length.<ref name="G" /> Hence, Gottfried and his co-workers tried to solve this issue by means of conducting new research and analysis to create a method for measuring the size of large sharks (including ''C. megalodon'') with much greater accuracy, which was published in 1996.{{cref|b}} Using this new method, the maximum size of megalodon was calculated to be {{convert|15.9|m|ft|0|lk=on}} with a body mass of more than {{convert|50|ST|MT|0|lk=on}}.<ref name="G" /> But this calculation was based on a 168 [[millimeter|mm]] (6⅝ [[inch]]) long upper anterior tooth, which was the biggest tooth in the possession of this team at the time. Since then, even larger ''C. megalodon'' teeth have been excavated which indicate that the shark could grow to more than {{convert|17|m|ft|0|lk=on}}.<ref name="H" /><ref name="S">{{Citeweb|last=Kowinsky|first=Jayson|title=The Size of Megalodons |url=http://www.fossilguy.com/topics/megsize/megsize.htm|year=2002|accessdate=2008-01-12}}</ref><ref name="N">{{cite journal|last=Riordon|first=James|title=Hell's teeth|journal=NewScientist Magazine|issue=2190|pages=32|date= June 1999|url=http://www.newscientist.com/contents/issue/2190.html}}</ref> Shark researcher Cliff Jeremiah also has suggested a method to determine the size of the large sharks, including ''C. megalodon'',<ref name="H" /> and his method is considered to be among the most reliable.<ref name="H" /> He suggested 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 proxy for estimating jaw perimeter. For every centimeter of root width of the largest tooth, he asserts, there was approximately 4.5 feet of the shark. He concluded that ''C. megalodon'' could grow up to {{convert|18.2|m|ft|0|lk=on}}.<ref name="H" /> Many scientists acknowledge this conclusion.<ref name="H" /><ref>{{Citeweb|last=Alter|first=Steven|title=Megalodon |url=http://www.megalodonteeth.com/html/article.html|date=1997|publisher=Fossil News - Journal of Amateur Paleontology|accessdate=2007-12-14}}</ref> Hence, from the research of several scientists, it is clear that ''C. megalodon'' is the largest macropredatory shark that has ever lived and is among the largest fishes known to have existed.<ref name="G" /> === Jaw dentition === [[Image:Mandibole Carcharodon Megalodon Miocene2.jpg|thumb|Side view of ''megalodon'' jaws]] Some scientists including Applegate and Espinosa published an artificial [[dentition|dental formula]] for ''C. megalodon'' in 1996.<ref name="D" /> Several modern ''C. megalodon'' jaw reconstructions are based on this dental formula. The dental formula of ''C. megalodon'' is: {{dentition2 |2.1.7.4|3.0.8.4}} As evident from the dental formula, the jaws of ''C. megalodon'' contained four different kinds of teeth.<ref name="D" /> * ''Anterior'' - (A) * ''Intermediate'' - (I) {{cref|c}} * ''Lateral'' - (L) * ''Posterior'' - (P) Paleontologists suggest that ''C. megalodon'' had a total of about 250 teeth.<ref name="H" /> === Skeletal reconstruction === Aside from estimating the size of ''C. megalodon'', Gottfried and his colleagues also have tried to determine how ''C. megalodon'' might have looked like in real life.<ref name="G" /> After conducting a comprehensive analysis of the available evidence, they concluded that ''C. megalodon'' was a very robust shark and it was more massively proportioned than many modern large sharks including ''C. carcharias'' due to several reasons including: * ''C. megalodon'' had a more massive, stouter and more strongly developed chondrocranium and jaws than those of modern macropredatory sharks, in order to functionally support a massive and very robust dentition.<ref name="G" /> * The fins of ''C. megalodon'' were significantly larger and thicker because they needed to be adapted for propulsion and control of movements of such a massive shark.<ref name="G" /> * It had a higher vertebral count than that of any large shark including ''C. carcharias''.<ref name="G" /> Gottfried and his colleagues eventually developed a model of the entire skeleton of ''C. megalodon'' with the above mentioned characteristics, which has been put on display in Calvert Marine Museum at Solomons island, [[Maryland]] in [[USA]].<ref name="G" /><ref name="C" /><ref name="PS">{{Citebook|last=Arnold|first=Caroline|title=Giant Shark: Megalodon, Prehistoric Super Predator|publisher=Houghton Mifflin|pages=18-19|date=2000|isbn=9780395914199}}</ref> == Distribution, range and habitat == ''C. megalodon'' was a [[pelagic]] fish and it thrived in all the [[ocean]]s of the world in its time, indicating dominance over the marine world. The teeth of this ancient shark have been excavated from many parts of the world, including [[Europe]], [[North America]], [[South America]], [[Australia]], [[New Zealand]], [[Japan]], [[South Africa]], [[Malta]] and [[India]].<ref name="H" /><ref name="D" /> ''C. megalodon'' most likely inhabited warm water regions around the world.<ref name="E" /> Its range would not have been constricted by its reliance on warm waters as the oceans were noticeably warmer during the [[Miocene]] and early [[Pliocene]]. This would have made it possible for this species to flourish around the world, as evident from the fossil records. == Paleoecology == === Diet === [[Image:MEG1.jpg‎|thumb|An artistic depiction of a ''Megalodon'' chasing two juvenile [[whale]]s.]] It is believed that ''C. megalodon'' would have had a huge appetite, which would be necessary for sustenance of its enormous bulk.<ref name="PS" /> It was contemporaneous with a large variety of marine animals, including various species of whales. Several whale vertebrae and bones have been found with clear signs of large bite marks made by the teeth that match those of ''C. megalodon''.<ref name="H" /><ref name="G" /><ref name="D" /> The teeth of ''C. megalodon'' are serrated,<ref name="H" /><ref name="A" /> which would have improved efficiency in slicing the [[flesh]] of prey items. Various excavations have revealed ''C. megalodon'' teeth lying close to the chewed remains of whales.<ref name="G" /><ref name="C" /> This evidence suggests a predator-prey relationship between ''C. megalodon'' and large marine animals including whales <ref name="D" /> (e.g. [[sperm whale]]s,<ref name="H" /> ''[[Cetotherium]]'',<ref name="E" /> and ''[[Odobenocetops]]''<ref>{{Citeweb|title=Fact File: Odobenocetops |url=http://www.bbc.co.uk/science/seamonsters/factfiles/odobenocetops.shtml|publisher=BBC|accessdate=2008-03-21}}</ref>), [[sirenian]]s,<ref name="H" /> [[dolphin]]s,<ref name="H" /> and [[pinniped]]s.<ref name="E" /> Like other sharks, ''C. megalodon'' was certainly [[piscivorous]] as well.<ref name="E" /><ref name="PS" /> === Behavior === Most sharks are opportunistic [[predator]]s and rely on a broad spectrum of prey coupled with scavenging. ''C. megalodon'' was unlikely to have been an exception to this rule.<ref name="E" /> Some large sharks (including the great white shark) employ ambush strategies against their prey during hunting. A shark usually attacks its prey with great force in the first attempt to inflict maximum possible damage. Then it circles its prey and waits for it to weaken, before dispatching it without facing any resistance. Some paleontologists suggest that ''C. megalodon'' also may have employed a similar hunting strategy against large potential prey, like adult whales. Several fossilized flipper bones, and caudal vertebrae of whales have been found with bite marks that were caused by the attacks from ''C. megalodon''.<ref name="H" /><ref name="G" /> This evidence indicates that ''C. megalodon'' most likely injured and immobilized its prey by biting off its propulsive structures, before proceeding to feed on it.<ref name="H" /><ref name="G" /> However, remains of a large prehistoric baleen whale have been excavated from [[Chesapeake Bay]], which provided the first opportunity to quantitatively analyse the feeding behavior of ''C. megalodon'', and this specimen revealed that the attacking behavior of ''C. megalodon'' may have been more aggressive than that of the great white shark.<ref name="N" /> One reason is that the shark apparently focused its attack on the bony portions of the prey, which great white sharks generally avoid.<ref name="N" /> From fossil evidence, juvenile ''C. megalodon'' individuals would mostly prefer to attack small-to-medium sized prey, such as [[porpoise]]s, other sharks, [[pinniped]]s and juvenile whales. Hence, through [[ontogeny]] ''C. megalodon'' proceeded to hunt larger animals.<ref name="G" /> In addition, fossil evidence suggests that the preferred breeding grounds of ''C. megalodon'' were mostly warm coastal regions.<ref name="G" /> == Extinction hypothesis == [[Image:Megalodon and fossil great white shark teeth.jpg|thumb|''Megalodon'' and fossil shark teeth]] There are several hypotheses as to how an apex predator like ''C. megalodon'' suddenly became [[extinct]] after millions of years of existence. However, the extinction of large-bodied marine predators, such as [[pliosaur]]s, [[mosasaur]]s, [[ichthyosaur]]s and ''[[Basilosaurus]]'', are instructive as to the possible mechanism involved. Scientists believe that ''C. megalodon'' disappeared due to a variety of reasons.<ref name="E" /> The geological and [[Climate|climatic]] conditions of the world when ''C. megalodon'' existed, were considerably different from those now. It is possible that these major climatic changes may have been unfavorable for ''C. megalodon''. Some notable climatic shifts are: * During the late Pliocene and Pleistocene epochs there were significant [[ice age]]s,<ref>{{Citeweb|title=Pliocene epoch|url=http://www.ucmp.berkeley.edu/tertiary/pli.html|accessdate=2008-01-16}}</ref><ref>{{Citeweb|title=Pliestocene epoch|url=http://www.ucmp.berkeley.edu/quaternary/ple.html|accessdate=2008-01-16}}</ref> which cooled the oceans significantly.<ref name="D" /> * From the fossil record, whale migatory patterns from the end Pliocene have been reconstructed, suggesting that some species migrated to [[polar region]]s, effectively "getting out of the range" of ''C. megalodon''.<ref name="E" /><ref name="D" /> * Prolonged disturbance of food chains can wipe out predators with massive metabolic requirements. During the Pliocene, some species of whales and dolphins (e.g. ''[[Odobenocetops]]'' and ''[[Cetotherium]]'') became extinct. As these species would most likely have been among the potential prey of ''C. megalodon'',<ref name="E" /> sustaining the dietary requirements of such a large predator would have become increasingly difficult. * In addition, wide-scale [[glaciation]] trapped much of the oceanic [[salt]] water during the late Pliocene and Pleistocene through-out the ice ages. At its height sea levels dropped significantly, restricting many shallow coastal areas, that have been thought to serve as breeding grounds for the ''C. megalodon'' pups.<ref name="E" /> Consequently, a hypothesis can be constructed, that at the end of the Pliocene, the polar seas became too cold for ''C. megalodon'' to survive. Several species of whales, including cetotheriids, became extinct during the late Pliocene, while some whale species showed a trend towards the cooler polar regions. Many of the shallow warm water regions dried out at that time, that may have been breeding grounds for ''C. megalodon''. As such, these significant disturbances in the [[ecosystem]] would have caused major problems for ''C. megalodon''. Being unable to follow the surviving whale species into the polar seas the food supply of ''C. megalodon'' lessened, which over time lead to the extinction of the species.<ref name="E" /> == Relict == [[Image:Carcharodontosaurus and Megalodon teeth.jpg|thumb|''[[Carcharodontosaurus]]'' tooth from the [[Sahara Desert]] with a ''C. megalodon'' tooth, and a 25 mm diameter coin ([[Quarter (United States coin)|US quarter]]).]] While scientists contend that available evidence shows that ''C. megalodon'' is [[extinction|extinct]], the idea of a [[relict]] population seems to have seized the public imagination.<ref name="H" /><ref name="E" /> Evidence supporting such ideas is generally seen as scant, ambiguous and lacking sufficient credibility.<ref name="H" /><ref name="E" /> ''C. megalodon'' teeth have been discovered that some argue date to as recently as 10,000 to 15,000 years ago. This claim is based on the discovery of two teeth from the [[South Pacific]] by the [[HMS Challenger (1858)|HMS ''Challenger'']] scientific expedition (these teeth were dated by estimating the amount of time it took for [[manganese]] to accumulate on them, although it is quite possible the teeth were fossilized long before being encrusted). Problems with this dating method include the simple fact that deposition of manganese oxide on the seafloor is not constant, and can only serve as a minimum age. In all likelihood, these teeth are probably much older.<ref name="E" /> Scientists now suggest that these recent estimates for these teeth are inaccurate, and being based on an outdated testing methodology. Another possible explanation is that some ''C. megalodon'' teeth might have been eroded from pre-Pleistocene deposits and re-deposited in the much younger strata, such as those from the late Pleistocene.<ref name="E" /> === Megamouth analogy === Some proponents of modern-day ''C. megalodon'' survival suggest that the shark might be lurking in the deep waters and often cite the case of the [[megamouth shark]] as an example and state that the oceans can still harbor large species unknown to man.<ref name="E" /> However, the research has suggested that the megamouth shark is a [[false analogy]] to the possible existence of ''C. megalodon'', unless the proposed individual was a highly specialized mesopelagic planktivore with poorly calcified skeleton; ''C. megalodon'' was certainly not such a creature.<ref name="E" /> Research concludes that ''C. megalodon'' was a large carnivorous shark that adapted to a warm and food-rich marine habitat and was an active predator of large animals like whales. Such a creature would not be able to survive in the cold, food-poor deep-sea.<ref name="E" /> === Supposed ''C. megalodon'' sightings === [[Image:Carcharodon megalodon.jpg|thumb|Man sitting on ''Carcharodon megalodon'' jaws]] Some relatively recent reports of large shark-like creatures have been interpreted as surviving ''C. megalodon'', but such reports are usually considered misidentification of [[basking shark]]s, [[whale shark]]s or [[submarine]]s. One well-known example was reported by writer David G. Stead in his book ''Sharks and Rays of Australian Seas'', that was released in 1963. The brief excerpt of this account is mentioned below: <blockquote> In the year 1918 I recorded the sensation that had been caused among the "outside" crayfish men at Port Stephens, when, for several days, they refused to go to sea to their regular fishing grounds in the vicinity of Broughton Island. The men had been at work on the fishing grounds---which lie in deep water---when an immense shark of almost unbelievable proportions put in an appearance, lifting pot after pot containing many crayfishes, and taking, as the men said, "pots, mooring lines and all". These crayfish pots, it should be mentioned, were about 3 feet 6 inches [1.06 m] in diameter and frequently contained from two to three dozen good-sized crayfish each weighing several pounds. The men were all unanimous that this shark was something the like of which they had never dreamed of. In company with the local Fisheries Inspector I questioned many of the men very closely and they all agreed as to the gigantic stature of the beast.<ref name="H" /><ref name="E" /> </blockquote> This report received considerable attention from the [[Mass media|media]], and David G. Stead himself believed in the account. Most shark experts, however, after careful examination of this account questioned its authenticity, as the sailors themselves were giving contradictory statements regarding the details of the event, including the size factor of the mystery animal. Hence, those sailors were most likely exaggerating the details of the event. One critic even said that those sailors might have concocted this story, after they lost their crab pots in an accident.<ref name="H" /> Another well-known account was reported by writer [[Zane Grey]] and his son Loren in 1933. His actual comments have been narrated by Gross in 1987: <blockquote> At first I thought it was a whale, but when the great brown tail rose in the ship’s wake as the fish moved ponderously away from the liner, I knew immediately that it was a monstrous shark. The huge round head appeared to be at least 10 to 12 feet across if not more ... It was my belief that this huge, yellowish, barnacled creature must have been at least 40 or 50 feet long. He was not a whale shark: the whale shark has a distinctive white purplish green appearance with large brown spots and much narrower head. So what was he---perhaps a true prehistoric monster of the deep?<ref name="E" /> </blockquote> After careful examination of this case, most shark experts concluded that Grey's description of the animal still closely matches that of the whale shark and he was wrong about the color of the animal. An expert, Castro, gives a good explanation of the coloring of the skin of whale sharks. He points out that many white or yellowish spots can be observed on the skin of whale sharks. Their heads are very wide, squarish, yet slightly rounded.<ref name="E" /> Another less well known incident was narrated by Cartmell in 1978. His narration is mentioned below: <blockquote> In the 1960’s along the outer edge of Australia’s Great Barrier Reef, an 85 foot [26 m] ship experienced engine trouble which forced it to weigh anchor for repairs. Although the men subsequently refused to openly report what they had seen for fear of public ridicule, the captain and his crew later told friends of sighting an immense shark as it moved slowly past their ship. Whitish in color, they were awed by its size. It was as long if not longer than their boat! Experienced men of the sea, they too were certain the creature was not a whale.<ref name="E" /></blockquote> The problem in this case is that no evidence has been provided by Cartmell to support his claim. Hence his narration has also been dismissed as unreliable.<ref name="E" /> Similarly a few other cases of ''C. megalodon'' sightings have also been presented but all of them have been declared to be false due to lack of convincing evidences.<ref name="E" /> == In fiction and popular culture == Ever since the remains of ''C. megalodon'' were discovered, it has been an object of fascination. It has been portrayed in several works of [[fiction]], including films and novels, and continues to hold its place among the most popular subjects for fictional works involving [[sea monsters]]. It is, however, interesting to note that in most of these works of fiction, ''C. megalodon'' is shown to surface from the vast depths of the oceans, either as a result of human intervention or through natural means. === Films === * ''Shark Hunter'' (2001) * ''[[Shark Attack 3: Megalodon]]'' (2002) * ''[[Megalodon (film)|Megalodon]]'' (2004) * ''Hai-Alarm auf Mallorca'' (2004) * ''Meg'' (to be released) === Novels === * ''Extinct'' Charles Wilson (1997) * The "Meg" series by [[Steve Alten]] (1997 - current) {{cref|e}} * ''[[The Trench]]'' Steve Alten (2000) * ''From the Dark Below'' Cari McKnight (2001) === Television === * ''[[Chased by Sea Monsters|Sea Monsters: A Walking with Dinosaurs Trilogy]]'' (2003) === Games === * ''Shark! Hunting the Great White'' (2001) * ''Sea Monsters Adventure'' (2003) === Music === * The metal band [[Mastodon (band)|Mastodon]] had a song entitled ''Megalodon'' on their album [[Leviathan (album)|Leviathan]]. == See also == * [[List of sharks]] * [[Prehistoric fish]] * [[List of apex predators]] == Notes == * {{Cnote|a| The oldest ''C. megalodon'' teeth found are about 18 million years old.<ref name="H" /> Though, ''C. megalodon'' became extinct in the Pliestocene epoch probably about 1.5 million years ago.<ref name="E" />}} * {{Cnote|b| The actual method is: "Megatooth's" Total Length in meters &#61; [&minus; (0.22) + (0.096) &times; (Slant height of tooth in [mm])].<ref name="G" /> Though, this method has often been interpreted as: "Megatooth's" Total Length in meters &#61; [(0.96) &times; (Slant height of tooth in [cm] &minus; (0.22))], because it yields same results.<ref name="S" />}} * {{Cnote|c| In the case of ''C. megalodon'', this tooth appears to be upper anterior and is technically termed as "A3" because it is fairly symmetrical and does not points mesially, but this tooth is still designated as an intermediate tooth.<ref name="A" /> However, in the case of the great white shark, the intermediate tooth does points mesially. This point has often been raised in the ''Carcharodon'' vs. ''Carcharocles'' debate regarding the ''megalodon'' and favors the case of ''Carcharocles'' proponents.}} * {{Cnote|d| The [[Jaws]] novel contains a lengthy discussion about ''C. megalodon'' and the possibility of its survival in modern age. However, such details were not added in the film version.}} * {{Cnote|e| The "Meg" series by Steve Alten is a work of fiction, which comprises of several novels. (See ''[[Meg: A Novel of Deep Terror]]'' article for more details)}} == References == {{reflist|2}} == External links == {{Commons|Megalodon}} {{Wikispecies|Carcharodon megalodon}} {{Sharksportal}} * [http://www.msnbc.msn.com/id/23833957/ Snorkeling teen finds ancient shark tooth] from MSNBC * [http://www.sdnhm.org/exhibits/mystery/fg_megalodon.html Fossil Field Guide, Carcharodon Megalodon] from San Diego Natural History Museum * [http://www.bbc.co.uk/science/seamonsters/factfiles/megalodon.shtml Fact File: Megalodon] from BBC, with pictures and video * [http://www.tellmewhereonearth.com/images/Web%20Photos/Megalodon_Jaw.BMP An impressive photograph of Megalodon's jaw] * [http://www.tellmewhereonearth.com/Web%20Pages/Sharks/Sharks%20Photos/Megalodon_jaw_Columbia_SC_museum.JPG Megalodon jaws on display in South Carolina State Museum] * [http://ww1.prweb.com/prfiles/2004/06/01/130554/Steve_in_BIGGEST_jaws_B___W.jpg The largest modern Megalodon jaw reconstruction in the world] (NOTE: Reconstructed by Vito Bertucci) === Educational videos === * [http://www.bristolfilmstudios.com/pages/perfect_shark/index.php A video clip of the Perfect Shark (2006) program] from [[BBC]] * [http://dsc.discovery.com/video/player.html?bctid=17041381 Long Ago, in the Chesapeake Bay] from [[Discovery Channel]] (NOTE: [[Adobe Flash Player|Flash Player]] required) * [http://www.youtube.com/watch?v=ZVOSVIt5HaU Paleoworld - Megalodon] (NOTE: [[Adobe Flash Player|Flash Player]] required) [[Category:Lamnidae]] [[Category:Miocene fish]] [[Category:Pliocene fish]] [[Category:Pleistocene fish]] [[Category:Prehistoric fish]] [[Category:Prehistoric sharks]] [[ca:Tauró de grans dents]] [[cs:Megalodon]] [[da:Megalodon]] [[de:Megalodon]] [[es:Carcharodon megalodon]] [[fr:Mégalodon]] [[ko:메갈로돈]] [[id:Megalodon]] [[it:Carcharodon megalodon]] [[he:מגלודון]] [[hu:Megalodon]] [[nl:Megalodon]] [[ja:メガロドン]] [[pl:Megalodon]] [[pt:Carcharodon megalodon]] [[ru:Мегалодон]] [[sk:Megalodon]] [[fi:Megalodon]] [[sv:Megalodon]] [[th:เมกะโลดอน]] [[zh:巨牙鯊]]