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28 June 2021
Perhaps no other shark besides the great white shark has captivated the public’s imagination more than the megalodon shark. This prehistoric shark has been the subject of many movies and stories since sharks became popular. These movies often depict them as great whites; but bigger, better, and nastier. And it is easy to see why -- it’s mostly because of the fossil remains uncovered by paleontologists. The megalodon is one of the largest and most powerful predators to have ever lived and the largest shark ever discovered. Many a megalodon horror story’s plots revolve around the idea that they still swim the world’s oceans, albeit at the hidden and undiscovered parts of it.
This article will discuss what the megalodon is and why did it become extinct. It will discuss the shark’s size, appearance, and diet. This article will also discuss why it became extinct, such as the sudden lack of prey due to changes in the global climate at the time. We aim to give readers more information on these magnificent creatures aside from what we see and hear from pop culture and movies.
To start things off, let’s answer the first part of the title. The megalodon shark (Carcharocles megalodon) was a species of megatooth shark that belonged to the Otodontidae family. Its name means “big tooth” in Greek. It was initially thought to be in the same family as the great white, the Lamnidae family, due to their similarities. But recent studies show that the megalodon is of a different one. It is believed by scientists that the megalodon serves as the link between earlier sharks and modern ones. That is why even today, there are conflicting theories on which family the megalodon belongs to.
Fossil records show that they existed between the early Miocene Epoch (23.03 million years ago) to the end of the Pliocene Epoch (2.58 million years ago). The megalodon was the undisputed apex predator of the world’s oceans for almost 13 million years before dying out three million years ago. Megalodon fossils have been discovered both in shallow and temperate seas, as well as along continental shelves across the world. It is only in Antarctica where there are no megalodon fossils are found. This could be explained by the large seaways that separated the continents during the Miocene Epoch (23 million to 5.3 million years ago), which allowed megalodons to travel from one place to another.
The megalodon is believed to have measured between 49.2 to 59.1 feet (15 to 18 meters) long and weighed roughly between 30 to 60 metric tons. Though these numbers are impressive, one should note that these are just rough estimations based on the fossils recovered by paleontologists. This is because a lot of the discovered megalodon fossils are mostly their teeth or vertebrae. So scientists estimate the shark’s size based on the size of their teeth instead.
Why is it that a lot of their remaining fossils are simply teeth? Shark teeth are both the hardest parts of the shark’s skeleton and it produces several of them. For just two weeks of eating, a shark can lose an entire set of teeth. And throughout their lives, sharks just kept growing more and more. This could mean that there are plenty of megalodon teeth lying around the ocean floor, waiting to be discovered.
The similarities between the shape of the great white’s and the megalodon’s teeth suggest that the latter must have looked similar to the former. This means that the megalodon must have been a large torpedo-shaped fish, with a conical snout, large pectoral and dorsal fins, and a crescent-shaped tail, just supersized. Later studies have debunked this theory, and propose that the megalodon belonged to a different lineage of sharks, with the megalodon being the last member. Other scientists also believe that the megalodon could have also resembled a basking shark, a sand tiger shark, or even a whale shark.
The megalodon’s teeth also tell us what exactly did the megalodon preyed upon. Its bite diameter is a staggering 9.8 feet (3 meters) wide, suggesting that its primary food source must have been large fish, whales, sea turtles, sirenians like dugong or manatees, or even other sharks. This shouldn’t already come as a surprise because of the megalodon’s large size. Prehistoric whale bones also support this theory, as they bore bite marks and even tooth fragments belonging to megalodons. Because they are the apex predator of their time, they must have also occupied the same ecological niche as the great white in the present. This also means that they didn’t have any natural predators, as they prey on everything below them.
Though we don’t know how megalodons mate, it is believed that megalodons gave birth to live young. They must have also reared them in nurseries, as one was discovered off the coast of Panama in 2010. This nursery may have allowed the younger megalodons to hunt smaller prey, while adults could better protect them from other predatory sharks like the hammerhead shark.
There are several reasons, scientists believe, as to why the megalodon became extinct. One reason was the extinction of a large part of the megalodon’s diet. As the Pliocene Epoch ended, the world’s temperatures began to cool down, leading to either the deaths or adaptation of their prey to colder waters. Because of this, the megalodon’s numbers began to dwindle due to the lack of food sources and competition from smaller sharks and killer whales. New studies have suggested that, ironically, it was the appearance of great whites that helped in the megalodon’s extinction. They were unable to compete with the smaller sharks for the remaining fish available in the ocean, which sped up their decline.
Another factor that helped in the megalodon’s decline - and later extinction - was climate change. Not the climate change that we’re familiar with, but the gradual cooling of the planet during the end of the Pliocene Epoch and the beginning of the Pleistocene Period. Because they are warm-water fish, this meant that megalodons found it harder to live in these waters. The Pleistocene Period, more commonly known as the Ice Age, is generally agreed as the time the megalodon became extinct, either that or during the Pliocene-Pleistocene Boundary (2.58 million years).
That said, no factor can be fully blamed for the extinction of the megalodon. As noted before, it was a combination of changes in the ecosystem, the loss of their main diet, and the cooling of the ocean that led to their extinction. And if you’re still hoping that at least a few of them are still around, frozen somewhere deep beneath the ocean, scientists have concluded that they can’t survive without being detected. A shark their size needs a lot of food to survive and they can’t survive long in cold, deep waters as they are warm-water fish.
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