What Actually Caused The Megalodon’s Extinction? Great White Sharks, Maybe.

Megalodon close-up
© racksuz/Shutterstock.com

Written by Alan Lemus

Published: December 6, 2022

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The Megalodon is the largest shark that ever lived and belongs to the same family as today’s great white sharks, mako sharks, and tiger sharks. This family is called Lamnidae, and the Megalodon was at its apex. 

The Megalodon lived around 20 million years ago and dominated the shark food web until its extinction some 3.6 million years ago. What are the possible causes of the Megalodon’s extinction?

The existence of great white sharks, food scarcity, climate change, a supernova, and predation contribute to major reasons leading to the Megalodon’s extinction. 

While you may have heard of the Megaladon in films, magazines, books, and more, we have researched what may have caused them to go extinct. Let us take a look at a few theories.

Megalodon hunting

The Megalodon lived around 20 million years ago and dominated the shark food web until its extinction some 3.6 million years ago.


1 – Climate Change

The Megalodon’s geographic range extended during the Miocene but declined during the Pliocene. At first, climate-related temperature fluctuations in the ocean were blamed for the reduction. Specifically, the shutting of the seaway between North America and South America around three million years ago. It altered the flow of ocean currents, plus other aspects of ocean circulation.

The belief is megalodons can not survive in the cooling oceans. Since warmer waters are ideal for sharks, many megalodons, the change in climate creates displacement.

In addition, researchers claimed that the Megalodon’s average internal temperature could have reached as high as 35 to 40 degrees Celsius, a significant increase from the temperatures in makos and great white ancestors, which ranged from 20 to 30 degrees Celsius.

The practical implication of the Megalodon’s high body temperature is that it would have possessed an exceptionally rapid metabolism, which would have required it to be constantly fed. Because of this, they would have been especially susceptible to the rising water temperatures or the subsequent movement of their prey to waters with colder temperatures.

But according to a group of American scientists, the Megalodon’s body size varied depending on its habitat. They suggested that the Megalodon grew larger in cooler waters than in warmer waters, correlating to Bergmann’s rule that animals living in colder climates are frequently larger because their larger size enables them to keep more heat.

Growing larger in cooler waters may have boosted the Megalodon’s ability to have a size advantage over its environment. The size advantage could have meant the ability to travel long distances and catch and feed on large prey, hence regulating its body temperature.

Because the Megalodon could not grow bigger in the warmer environment before the climate change, it could not swim to longer distances, catch larger prey, and regulate its internal temperature.

2 – Great White Shark’s Evolution

While the reasons for this massive animal extinction remain a mystery, a 2019 study highlighted the possibility that the great white shark’s evolution played a role. 

Further supporting the idea that the infamous great white shark is responsible is a study in Nature Communications.

Even though it is speculated that great white sharks hunted megalodons, they probably didn’t try to devour them due to body size differences. The Megalodon was about twice as large as the great white shark.

Megalodons shared many characteristics with great white sharks and makos. This includes the solid jaws and sharp teeth that they used to hunt various types of fish and squid. This is how they got most of their food in prehistoric times.

But megalodons are believed to have been wiped out because of food competition with great white sharks

The fact that both megalodons and great white sharks could swallow whole their prey led to direct competition between them. 

Since they ate similar species, this competition strongly favored the great white sharks over the Megalodon.

It is believed that great white sharks had more efficient hunting skills than megalodons, and their smaller size made that possible. Since the great white shark outcompeted many of its predecessors when catching prey, it has survived till today.

3 – Food Scarcity

Climate change could have affected the Megalodon’s prey by forcing them to relocate to warmer waters, reducing their population. At the time the Megalodon went into extinction, it was discovered that about 35% of sea birds went into extinction, alongside about 45% of sea turtles. Sea turtles and birds were potential megalodon prey. The extinction of some of them could have been a hunger threat to the mega shark.

It is also believed that the evolution of orcas could have caused the Megalodon’s extinction. Before the appearance of orcas (killer whales) around five to 10 million years ago, slow-moving whales served as the primary food source for the Megalodon. But the slow-moving whales went extinct in the same period that killer whales evolved.

The number of megalodons may have started to decline as a result of such food loss and competition.

Megalodon chasing dolphin

The number of megalodons may have started to decline as a result of such food loss and competition.

©Esteban De Armas/Shutterstock.com

4 – Predation

The effects of a shifting global landscape were depleting the amount of prey that could be found in the oceans. Because of this, top predators or other large carnivores began to compete with one another for the limited resources available for food. This resulted in interactions between species that otherwise wouldn’t have had any reason to come into contact with one another.

It is believed that the Megalodon became a meal for smaller predators whose territories had recently overlapped with the Megalodon. The smaller predators (carnivores) hunted in groups, and it is believed that they could have invaded and killed some megalodons.

5 – A Supernova

Approximately 2.6 million years ago, a powerful supernova erupted in the earth’s vicinity, nearly the same as the Megalodon’s extinction. Research linked the supernova to a global extinction of aquatic megafauna after investigating a rise in radioactivity. It would have resulted in severe health issues, such as tumors and mutations, for large sea species.

It’s conceivable that our solar system was utterly destroyed by this supernova, which occurred 150 light years away. Even though the earth’s solar system is not even a light year in diameter, the unimaginable amount of energy released by the supernova at that distance is more than enough to affect the earth severely.

According to the study’s findings, a wave of cosmic energy out of the explosion of that star would have reached earth after a few hundred years, and long after, the supernova has disappeared from the earth’s sky.

According to the researchers’ findings, the shower of particles blasted the atmosphere, which led to changes in the climate. This caused the extinction of enormous ocean species in vast numbers, including the Megalodon.

gamma-ray bursts

It’s conceivable that our solar system was utterly destroyed by this supernova, which occurred 150 light years away.

©National Science Foundation / Nicolle Rager Fuller of the NSF – Original / License

Why Megalodons Could Not Exist Today

In the past decade, discoveries have been made that provide evidence that this giant shark still exists today in the deep ocean waters of the planet. The most startling of these was in 2003, when Japanese researchers captured a live specimen on video that was estimated to be 50 to 60 feet long. 

But there are several reasons why these creatures cannot exist today.

Its Enormous Size

We can easily conclude that the Megalodon does not exist today. The creature was so giant that if it still existed today, we could easily spot it. 

The Megalodon was enormous, from sixty to eighty feet long and weighing in at seventy tons. An animal that large would be hard to miss. People would notice if it were alive today, and the researchers would have tracked down the creature.

Its Massive Jaws and Razor-Sharp Teeth

The Megalodon had massive jaws and razor-sharp teeth that were perfect for eating other sea creatures. If a megalodon existed today, we would notice telltale bite marks on other large marine animals, but no such bite marks have been found.

Scattered Teeth on the Ocean Floor

If these creatures were still there today, their enormous teeth would still be scattered throughout the ocean floor in the tens of thousands. This is because megalodons were continually shedding their teeth and growing new ones.

It Thrived in Warm Waters

The Megalodon, native to warm seas, would not endure the cold temperatures of the ocean’s depths, where it would have a greater chance of evading detection.

Megalodon tooth

Comparison of fossilized Megalodon and Great White Shark teeth.


What Exactly Did the Megalodon Look Like?

The Megalodon has been shrouded in mystery for a long time. For example, did it have to be warm-blooded to have such a large body? How did it go about catching its prey? 

Given that it was so enormous, how could it navigate the ocean depths? And given that it lived tens of millions of years ago, how could we possibly know what it looked like? 

Recent scientific discoveries are finally beginning to unravel the mysteries of the Megalodon.

Scientists could accurately figure out what Megalodon looked like by studying the physical remains of its prey and using computer programs to piece together its skeletal structure. They determined that the Megalodon was a streamlined creature with smooth, overlapping scales running along its entire body.

The Megalodon’s eyes were small and placed on the sides of its head so it could see in all directions. The positioning of its eyes also suggests that the giant creature relied on sight rather than smell when hunting prey.

The Megalodon’s conical snout was narrow at the tip and wide at the base, much like an almond. However, unlike the teeth of other large sharks, the Megalodon’s teeth are cone-shape with serrated edges and a blade-like cusp at the end. They were designed to shear prey into pieces rather than hold it in place while it was eaten whole.

Body-Size and Strength

Megalodon sharks were enormous. The longest was around 60 feet. The heaviest, if it weighed as much as a railroad car, could weigh as much as 50 tons. 

On aggregate, female megalodons reached 44 to 56 feet, while males were only approximately 34 to 47 long. Estimates of the Megalodon’s size use connections between its tooth size and body length because no cartilage remains exist.

Mouths Opened Wide

The Megalodon needed a wide mouth opening to successfully hunt prey as enormous as whales. Predictions state that its jaw would stretch nine to 11 feet wide. This means it would have no problem swallowing two adults side by side.

There were 276 teeth in those jaws. The estimates of the shark’s biting power suggest it was likely one of the fiercest predators ever.

Megalodon open mouth

Predictions state that its jaw would stretch nine to 11 feet wide.

©Gil Cohiba/Shutterstock.com

Diversity and Evolution

The first evidence of sharks in the fossil record dates back about 420 million years when the first modern fishes appeared. Then, almost all marine organisms lacked a backbone. Instead, trilobites, related to spiders and fiddler crabs, ran across the ocean floor. At the same time, shelled cephalopods, cousins of squid and jellyfish, dominated as the apex predators higher up in the water columns.

During the Carbonaceous and Permian ages, sharks of every sort could swim in the oceans around the planet. Then, about sixty million years ago, the Megalodon’s ancestors arrived. Even the most ancient member of the Megalodon had a body length bigger than today’s great white shark.

For a long period, scientists were under the impression that the great white shark had been the Megalodon’s closest living relative. 

There is a possibility that these two species coexisted at some point. Recent research proves the Megalodon has a close connection to mako sharks. They are smaller but faster fish-eating sharks.


The megalodon species could thrive in warm tropical and subtropical environments worldwide. Furthermore, its teeth have been discovered on all continents except Antarctica, indicating that the species inhabited a relatively large area.

Many megalodon teeth have been discovered off the eastern coast of North America, along the coastlines, and at the bottom of salty streams and rivers in North Carolina, Southern Carolina, and Florida.

The Megalodon’s Food

The Megalodon was a terrifying animal that preyed on other animals. Due to its status as the most extraordinary animal then, it consumed a wide variety of prey, including toothed whales, seals, sea turtles, and other sea creatures. Due to its opportunistic nature, it may also have fed on fish and other sharks.

The gashes can identify megalodon teeth they leave in whale fossils. Sometimes, a whole tooth is found embedded in the whalebone. According to research, a megalodon’s bite had about 40,000 pounds of force, making it the most substantial bite ever recorded.

Analyzing these tooth impressions can give insight into Megalodon’s diet. For example, the massive megalodon teeth could break through the thick ribs of larger prey, such as small whales, when the animal attacked them in the chest. Alternatively, they probably snubbed smaller victims with their snouts to render them unconscious before biting them.


Like the current bull sharks, megalodons had to have their young in particular nursery settings, such as sheltered estuaries and beaches. These areas supplied the young sharks with an abundance of fish to eat and a protected environment to develop. This shielded them from the predators that inhabit the open sea and offshore zones. 

Researchers have found potential nurseries for megalodons in four locations: The Canary Islands, Panama, Florida, and Maryland.

Key Take-Aways

The Megalodon might have gone extinct due to food scarcity. However, not only was there food competition for the scarce fish in the ocean, but sharks with traits better adapted to their habitat were more likely to survive in the long run. The Great White Shark is one of these sharks with features that are better able to cope with food scarcity. They are one of the top predators within the aquatic ecosystem today.

Up Next…

Take a look at a few of our other articles about this giant creature.

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About the Author

Alan is a freelance writer and an avid traveler. He specializes in travel content. When he visits home he enjoys spending time with his family Rottie, Opie.

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