Megalodon Shark – Interesting Facts and Features
For more than 20 million years, the ocean was the home to a monster shark called Megalodon. It was one of the most enormous, most feared sharks in the history of the earth, and then all of a sudden, this shark went on extinction. How? And why? Many people have different opinions about what happened to this shark. But, before we get into arguments about what did and what didn’t happen, let’s talk about these sharks’ facts and the mysteries surrounding them.
Megalodon shark whose scientific name is Carcharocles megalodon is a shark that lived 20 or more million years ago. This period includes the Early Miocene to Pliocene. Scientist first thought this shark belonged to the family of Lamnidae and were a close relative to the great white sharks. However, recent research argued that the megalodon shark belongs to the extinct family of Otodontidae. This is a diverge from the ancestry of the great white sharks during the cretaceous era. Authors are still debating this shark’s genus, with some placing it in either Megaselachus, Carcharocles or Procarcharodon.
Gigantic triangular fossil frequently found embedded in rocky formations were once believed according to renaissance accounts to be glossopetrae or petrified tongues of snakes and dragons. Danish naturalist, Nicolas Steno, corrected the theory. He identified them as shark teeth and produced a picture of a shark head having such teeth. All of his findings and descriptions are in the book titled “The head of a shark dissected”. This book also contains an illustration of megalodon teeth.
Louis Agassiz, who is a swiss naturalist, was the one who gave this shark its original scientific name. This came in his 1843 work, “Recherches Surles poisons fossils” which based on tooth remains. In 1837, Edward Charlesworth, who is an English paleontologist; used the name “Carcharias megalodon”. He cited Agassiz as the author, showing that Agassiz identified the species before 1843. Charles Daves Sherborn, an English Paleontologist in 1928, listed an 1835 series of Agassiz articles as a first scientific description of Megalodon shark.
The name “Megalodon” is from an ancient Greek word, meaning “Big tooth”. These shark teeth morphologically relate to that of the great white sharks (Carcharodon Carcharias). Based on observation, Agassiz placed Megalodon in the genus Carcharodon. Although Megalodon is a common name for the fish, it is still sometimes dubbed as the great white shark or megatooth shark.
Evolution of the Megalodon Shark
The earliest megalodon shark remains according to the report was around 28 million years ago (mya) from the late Oligocene. However, there is a significant argument as to when it appeared. Hence, date variations ranging to as young as 16 (mya). Scientists first thought megalodon sharks became extinct around the end of Pliocene. As such, claims of Pleistocene megalodon teeth that are younger than 2.6 million years are said to be unreliable. Moreover, recent research already moved the extinction date backward to earlier in the Pliocene, 3.6 mya.
Megalodon now considered to belong to the family of Otodontidae, the genus of Carcharocles; contrary to its earlier classification into Lamnidae and the genus Carcharodon. The previous classification of megalodon shark into Carcharodon was due to the dental similarity with the great white shark. But many authors now believe it is due to convergent evolution.
Using this model, the great white shark is more similar to the broad-toothed mako (Isurus hastalis) which is now extinct than the megalodon sharks. There is more similar dentition in those two sharks than to megalodon sharks. The Megalodon shark has more excellent serrations than the great white sharks. However, proponents of the former model would argue that the difference between megalodon shark teeth and that of the great white shark is obscure and minute.
The Megalodon Shark Appearance
The first interpretation of megalodon sharks was that they are robust looking. And, they have a similar build like that of the great white sharks. The jaws may have been broader and blunter than the great white shark. And, the fins thicker and similar in shape to that of great white sharks due to size. It may have had a deep-set eye that gives it a pig-eyed appearance.
The second interpretation is that the megalodon shark is similar to Rhincodon typus, which is the whale shark or the basking shark (Cetorhinus maximus). The anal-fin and the second dorsal fin would have been small, and the tail crescent-shaped. This shark would have had a caudal keel present on either side of their caudal peduncle which is their tail fin. Similar to other large sharks this build is an adaptation to reduce drag while they swim.
Researchers calculated the estimate of Megalodon using the statistical relationship between the size of its fossil teeth and that of modern white sharks. These statistics suggest that matured megalodon adults had a mean length of 33.5 feet (10.2 meters) and the largest measuring up to 82 ft (25 m) long. Studies estimate the adult body mass to range from 30 metric tons to 65 metric tons.
The adult females being larger than the males both in length and weight. There is every possibility that megalodon body size and behaviors vary around the globe. That is if it indeed attained a size of about 52 ft (16 m). Megalodon shark would have been the largest fish in history, surpassing even the Jurassic fish (leedsichthys).
Distribution Range and Habitat
The fossil remains of megalodon sharks have been found in temperate seas along the coastlines; shallow tropical waters and in continental shelf regions in all continent except Antarctica. During the early and middle parts of Miocene epoch which lasted from 23 to 5.3 million years ago, large seaways separated from South America to North America, from Europe to Asia and from Africa to the middle east which possibly facilitated movement from one ocean basin to the other.
Also, during the Miocene, the distribution of megalodon fossils expanded from pockets located in Mediterranean seas and the Caribbean in the Bay of Bengal. Then, along the coasts of California and southern Australia to encompass waters off the shores of South America, northern Europe, and East Asia. During the Pliocene Epoch, Megalodon’s geographical range contracted and then by the end of the epoch, it was extinct.
The Megalodon arguably could endure low temperatures due to mesothermal. This is the physiological capability of sharks to conserve metabolic heat by maintaining a higher body temperature than their environment.
Megalodon lived in a wide range of shallow coastal waters, swampy coastal lagoons, areas of coastal upwelling and offshore deepwater environments. Their adults were not abundant in shallow water environments. As such, mainly inhabiting offshore waters. Megalodon in its lifetime may have moved between oceanic waters and inshore waters mostly in different stages of its life cycle.
Dentition and Bite Force of the Megalodon
Teeth are the most common fossils of Megalodon. Their diagnostic characteristics include robust structure, triangular shape, fine serrations, large size, a visible V-shaped neck and a lack of lateral denticles. The Jaw and the teeth meet at a steep angle which is similar to the great white shark.
Connective tissue fibers anchored the tooth and then the roughness of the base may have added to their mechanical strength. The part facing the tongue, which is the lingual side of the tooth, was convex. And the other side of the tooth which is the labial was slightly flat or curved too. The anterior teeth were almost symmetrical and perpendicular to the Jaw.
On the other hand, the posterior teeth were asymmetrical and slanted. Megalodon shark teeth can measure up to over 7.1 inches (18 cm) slant height and are the largest of all known shark species. In Saitama, in 1989, there was a discovery of an almost complete set of megalodon teeth. Fossils of Megalodon were found from Yorktown formations in the united states, and it served as the principal basis of the jaw reconstruction at the national museum of natural history.
Megalodon had a sturdy dentition that they had about 250 teeth in their Jaw. There is every possibility that megalodon individuals had jaws spanning about 6.6 ft across. Megalodon teeth were serrated, which would have likely improved the efficiency in cutting through bone or flesh.
A team of scientists led by S. Wroe researched to determine the bite force of the great white shark in 2008. They used an 8.2 ft long specimen and then isometrically scale the result for its maximum size to determine the minimum and maximum body mass of Megalodon. Megalodon bite force was between 24,395 to 40,960 lbf (108,514 to 182,201 newtons) when placed in a posterior bite compared to the 4,095 lbf (7,400 newtons) bite force of the most massive known great white shark.
Furthermore, Wroe and his colleagues pointed out that sharks usually shake sideways while feeding, which would have amplified the force causing the total effect experienced by the prey to be higher than the estimate.
The Internal Anatomy of Megalodon
In the fossil record, vertebral centra, coprolites, and teeth represent Megalodon. Like all other sharks, their skeleton formation was from cartilage instead of bone. Therefore, most fossil specimens are preserved poorly. For Megalodon to support its hefty dentition, its jaws would have been stouter, massive and more strongly developed compared to that of the great white shark which possesses gracile dentition.
Its cartilaginous skull, chondrocranium would have been more robust in appearance and blockier compared to that of the great white shark. Some Megalodon fossil vertebra has been found. The most famous example is the partially preserved vertebral column of a single specimen, unearthed in Antwerp basin, Belgium in 1926.
Mature males of megalodon shark may have had a body mass of 13.9 to 37.4 short tons, and the adult females may have been 30.2 to 65.5 short tons. This goes with the speculation that females could range in length from 44 to 56 ft and males 34 to 47 ft.
A 2015 study, linking shark size and distinctive swimming speed, estimated that Megalodon would have swum at 18 kilometers per hour. This considers its body mass at distinctively 48 metric tons which are coherent with other sea creatures of its size like the fin whale which typically swims at speeds of 14.4 to 21.5 km/h.
The megalodon size may have been due to the abundance of large prey items and climatic factors. And, it also may have been due to the evolution of mesothermal which would have increased its swimming speed and metabolic rate. Megalodon was thought to be ectothermic because they shared a close relationship with otodontid considered to be ectotherms.
Contrary to this opinion, the most significant contemporary ectothermic sharks like the whale shark are filter feeders which implied that there are some metabolic constraints with their predatory lifestyle. Which means it is unlikely that the megalodon shark was ectothermic.
Maximum Estimates of Megalodon
A researcher Gordon Hubbell from Gainesville, Florida, has in his possession an upper anterior megalodon tooth whose maximum length is 7.25 inches (2.2 m) and it is one of the largest known tooth specimens from the shark. Furthermore, a 9 by 11 ft megalodon jaw reconstruction developed by Vito Bertucci, who is a fossil hunter, contains a tooth whose maximum height is allegedly over 7 in (18 centimeters).
Bashford Dean attempted first to reconstruct the Jaw of Megalodon in 1909, and it was displayed at the American Museum of Natural History. It was hypothesized from the dimension of the jaw reconstruction that Megalodon could have approached a 98 ft in length. Bashford dean had overestimated the size of the cartilage on each side of the jaws causing it to be too tall.
John E. Randall who is an ichthyologist, in 1973 used the vertical blade distance from its tip to the base of the enamel portion of the tooth to measure the length of Megalodon, and it yielded a maximum length of 43 ft. Nevertheless, tooth enamel does not necessarily increase in proportion to the shark’s total length.
In 1994, Patrick J. Schembri, a marine biologist, and Stephen Papson had the opinion that C. megalodon may have reached a maximum of around 79 to 82 ft (24 to 25 meters) in total length.
Shark researchers Leonard Compagno, S. Curtis Bowman, and Micheal D. Gottfried in 1996 plan a linear relationship between a total shark length and the height of the largest upper anterior tooth. The relationship they proposed is total length in metres = – (0.096) X (UA maximum height [mm] – (0.22). They affirmed that C. megalodon could have reached a maximum of 67 ft in total length.
“Clifford Jeremiah, a shark researcher in 2002, proposed that total length was proportional to the root width of an upper anterior tooth”. He claimed that for every o.38 in f root width there are approximately 4.6 ft. Clifford Jeremiah pointed out that the jaw perimeter of a shark is directly proportional to Megalodon’s total length with the width of the giant tooth being a tool for estimating the jaw perimeter.
In 2002, Kenshu Shimada also, a paleontologist of DePaul university proposed a linear relationship between total length after conducting an anatomical analysis of various specimens and tooth crown height, letting any sized tooth be used. Shimada also stated that the previously proposed methods were based on less. In essence, reliable evaluation of the dental homology between the great white shark and Megalodon and the growth rate between the root is not isometric and the crown, which he considered in his model.
In 2019, Kenshu shimada revisited his old work, and he discouraged using non-anterior teeth for estimations. He stated that the maximum total estimates length based on the upper anterior teeth are available in museums are 47 and 50 ft which depends on the estimation method used.
What did Megalodon Shark Eat Before They Went on Extinction?
Emma Bernard, who curates museum fossil fish collection opined that Megalodon would have eaten meat most likely large fish and whales and maybe other sharks too. There is also other evidence of Megalodon’s feeding habits which are in the form of fossilized whale bones. Marks of megalodon teeth are incised on the surface. Others also include broken teeth off in the bone during the eating frenzy that occurred millions of years back.
Emma further explained that for megalodon sharks to tackle preys as large as whales, they have to open broad. Also, he estimated that its Jaw would span 2.7 by 3.5 meters wide, which is big enough to swallow two adult human side by side without any issues. Researchers think these sharks would first attack the tails and flippers of the mammals to prevent them from getting away, then go to finish them off. Megalodon’s 276 serrated teeth were perfect for ripping apart flesh.
Why are there Megalodon Teeth All Around?
Almost all the fossil remains of these sharks are teeth. Sharks produce teeth throughout their lifetime. They also lose teeth every one or two weeks depending on what they feed on. This means they get up to about 40,000 teeth throughout their entire lives. Therefore, Shark teeth are continuously raining down to the seafloor. Thus, increasing the chance that they will become fossils. Also, teeth are the hardest part of a shark’s skeleton. Hence, their teeth contained entirely soft cartilage-like human nose and ears.
Relationships with Preys
Although, sharks are opportunistic feeders, Megalodon’s high-speed swimming capability, great size, powerful jaws with incredible feeding apparatus, made megalodon apex predator. Therefore, it is capable of consuming a broad spectrum of animals.
Megalodon was likely one of the most powerful predators to have ever existed. Research that focused on calcium isotopes of extinct and extant elasmobranch rays and sharks revealed that this shark fed at a higher trophic level compared to a contemporaneous great white shark. This means it was higher up in the food chain. Fossil remains have indicated that Megalodon preyed upon dolphins, cetotheres, small whales, bowhead whales, sperm whales, rorquals.
Furthermore, they also targeted seals, sea turtles, and sirenians. This shark was piscivorous and an opportunist. Teeth of Megalodon have been found near many whales’ bones with deep gashes. Several excavations have revealed the teeth of Megalodon lying close to the chewed remains of whales.
Megalodon feeding ecology varied with age between sites, including the modern great white shark. It is credible that the matured adults of the megalodon population off the coast of Peru targeted majorly cetothere whales 8.2 to 23 ft in length.
Strategies for Feeding
Sharks are known to employ sophisticated hunting strategies to engage large prey. The great white shark hunting habit could be similar to how Megalodon hunted their victims. The bite marks on whale fossils indicated that Megalodon employed different hunting strategies against their large prey. Several fossilized tail vertebrae and flipper bones have been found with megalodon bites which suggested that Megalodon would immobilize a whale before killing it.
Interaction with the Environment
This shark faced a highly competitive environment. Megalodon’s position at the top of the food chain possibly had an essential impact on the structuring of marine communities. Juvenile Megalodon preferred situations where small cetaceans were exuberant.
Megalodon may have subjugated white sharks to competitive exclusion. The fossils’ records showed that other shark species avoided regions where Megalodon inhabited by majorly keeping to the colder waters every time. Megalodon also likely had the tendency of cannibalism like the great white shark.
During the time Megalodon existed, the earth experienced several changes that affected so Many marine lives. A cooling trend beginning in the Oligocene 35 mya finally led to glaciation at the poles. Geological events changed precipitation and changed currents. Among these were changes in the Tethys ocean and the closure of the Central American Seaway, adding to the cooling of the oceans.
The gulf stream stalling prevented nutrient-rich water from reaching major marine ecosystems which may have possibly affected megalodon food sources. The enormous fluctuations in sea levels in the Cenozoic era happened in the Pilo-Pleistocene. That is around 5 million to 12 thousand years ago because of the expansion of glaciers of the poles which harmed coastal environments. Hence, suspected to be one of the reasons why Megalodon went on extinction.
The changes that occurred in the water may have affected the suitable shallow warm nursery sites megalodon sharks were so used to. It may have also hindered their rate of reproduction. Nursery areas are critical for many sharks in that it protects their juveniles from predation.
Also, the megalodon range did not extend into colder waters which may have affected them. This is because they may not have been able to retain an essential amount of metabolic heat. As a result, its range was restricted to blenching warmer waters. Their fossil remains have been significantly absent in regions around the world where the temperatures of the water had declined during Pliocene.
Could Megalodon still be Lurking Around in the Deep Oceans?
No, contrary to what discovery channel has said in the past, this shark can’t be somewhere lurking around. If Megalodon were still somewhere lurking around in the ocean, there would have been like telltale bite marks on other mammals, and as vast, as their teeth are, would have continued to liter around the sea in tens of thousands. Not to mention, that Megalodon can’t stand cold waters of the deep which is the only place it could be without getting noticed.
When did Megalodon go on Extinct?
There are no accurate data that could pinpoint the exact date this shark went on extinct. But research indicated that all signs of their existence ended 2.6 million years ago in the current fossil record.
Territoriality and Reproduction
Researchers are not exactly sure if Megalodon were ovoviviparous or viviparous. However, they thought them to have produced live young ones. Their body size estimate using fossils of their juveniles suggests that their newly birthed may have been at least 6.6 feet in length. There is little information about how individuals mate after they reach maturity.
Megalodon Interesting Facts
- There is no evidence of Megalodon’s continued existence in shallow waters that served as their hunting and nursery grounds.
- Fossils of this shark have been found around the world except for Antarctica.
- Female Megalodon may have been twice the size of the males.
- Dinosaurs and Megalodon did not co-exist. They were separated by more than 30 million years.
- Megalodon was the largest predator that ever existed.
- Megalodon and the great white shark are not closely related like it was thought of before.
- They ate mammals as big as whales for breakfast.
- Their teeth are the only most familiar fossils of them.
- Megalodon became extinct around 2.6 million years ago.
- This shark had the most powerful bite ever seen.
- Megalodon had about 276 teeth in 5 rows, and they shed teeth every week or two weeks.
Further Reading and references
- “Megalodon”, wikipedia. (Accessed 17 March, 2020).
- “Giant Megalodon Shark”, Museum of Arts and Sciences.
- “Megalodon: Facts about the long-gone, giant shark”, LiveScience.
- “The Megalodon Carcharocles megalodon“, Ocean Life.
- “Megalodon: the truth about the largest shark that ever lived, National History Museum. (Accessed 17 March 2020).