Megalodon, a compound of Greek root words, means “giant tooth,” is the common name for either Carcharocles megalodon or Otodus megalodon, truly gigantic predatory shark that went extinct long ago. For twenty million years, the world’s oceans were home to them until suddenly, they disappeared. This huge sea creature of ancient history has inspired a host of books, documentaries, and blockbuster films, some of which like to imagine that this super predator is still alive today, lurking somewhere out there in the mysterious deep.
Megalodon might not even have been the largest predator in the ocean at the time it was alive – the Leviathan whale (Livyatan melvillei) was potentially larger than Megalodon and occupied the same territorial waters. The Leviathan was likely a close ancestor of modern sperm whales, but it was a true apex predator with the largest teeth of any known animal (more than twice the size of the Megalodon’s) and used a similar hunting strategy of modern orca whales. The best current estimates put Megalodon at a maximum size of about just under 18 meters in length, with a weight of 30 to 50 tons. It is important to remember that because sharks do not have bone skeletons, no Megalodon skeleton fossil has ever been found and these estimates are based almost entirely on their tooth size and by using the size of their teeth as a comparison to other sharks. Also, keep in mind that Megalodon, like most animals, rarely reached its maximum size and most of these sharks would have been far smaller. Recent peer-reviewed studies indicate that Megalodon may have been significantly smaller than previously thought, probably reaching 14.2, – 15.3m. We do not need to look back in time to find a predatory whale larger than Megalodon: Present-day sperm whales have been recorded reaching 20.7m – far longer than Megalodon.
Unlike some other marine predators from prehistoric times—which were restricted to coastlines or inland rivers and lakes—the megalodon had a truly global distribution. Fossil remains of megalodon have been found in shallow tropical and temperate seas along the coastlines and continental shelf regions of all continents except Antarctica. Scientists have discovered megalodon nursery habitats in Panama, Maryland, the Canary Islands, and Florida. Like the modern-day bull shark, megalodons gave birth in specific nursery habitats that included protected bays and estuaries. These locations provided the shark pups with plenty of fish and a safe environment to grow, away from the larger predators of the Open Ocean and offshore zones.
Most of what we know about the Megalodon comes from studying its teeth. Nearly the entire skeleton of sharks is made from soft cartilage, it takes special conditions for this to preserve. The teeth, however, are made from a much tougher material known as dentin, which is harder and denser even than bone. While this enables a powerful bite, it also increases the chance that the teeth will fossilize as they are less likely to decompose. Every shark, including the megalodon, has several rows of teeth lining its jaw. Unlike people, who have a limited number of teeth in their lifetime, shark can lose and replace thousands of teeth in its lifetime. They constantly shed their teeth and replace them with new ones. Megalodon teeth are no different.
The largest megalodon tooth measures around 7 inches (17.8 centimeters) in length, which is almost three times longer than those of great white sharks. A more common size for megalodon teeth found is between 3 and 5 inches. Megalodon’s prey list is almost identical to the prey of modern killer whales. It fed on other big marine mammals, like whales, seals, dolphins, dugongs, and turtles. According to Discovery, it may have even eaten other sharks. The megalodon would first attack the flipper and tails of their prey to prevent them from swimming away, then go in for the kill. The megalodon’s 276 serrated teeth were the perfect tool for ripping flesh. These sharks also had a ferocious bite. While humans have been measured to have a bite force of around 1,317 newtons, researchers have estimated that the megalodon had a bite force between 108,514 and 182,201 newtons.
While the popular 2018 movie, “The Meg,” pits modern humans against an enormous megalodon, it is actually more than likely that the beast died out before humans even evolved. But it is difficult to pinpoint the exact date that the megalodon went extinct because the fossil record is incomplete. In 2014, a research group at the University of Zurich studied megalodon fossils using a technique called optimal linear estimation to determine their age. Their research found that most of the fossils date back to the middle Miocene epoch to the Pliocene epoch (15.9 million to 2.6 million years ago). For comparison, our earliest Homo sapiens ancestors emerged only 2.5 million years ago, during the Pleistocene epoch. Although much rarer than fossilized teeth, fossils also exist of whale bones with Megalodon tooth slashes and bites in them. There is none of these types of fossils from the last 2.6 million years. There is also no contemporary evidence from carcasses or bodies of whales of bite marks or wounds consistent with a large shark like Megalodon. Because no one has discovered any recent evidence of the monster — not even fossils that are any younger than 2.6 million years old — scientists agree that megalodons are long gone.
The cooling of the planet may have contributed to the extinction of the megalodon in a number of ways. Scientists contend that up to a third of all large marine animals, including 43% of turtles and 35% of sea birds, became extinct as temperatures cooled and the number of organisms at the base of the food chain plummeted, resulting in a knock-on effect to the predators at the top. As the adult sharks were dependent on tropical waters, the drop in ocean temperatures likely resulted in a significant loss of habitat. It may also have resulted in the megalodon’s prey either going extinct or adapting to the cooler waters and moving to where the sharks could not follow. . Precisely when the last megalodon died is not known.
So far, we have only found teeth and vertebrae of megalodons. There’s still lively debate in the scientific community about the modern species of sharks to which megalodon is most closely related. Scientists who have been studying modern sharks are working with paleontologists to study megalodon and other long-extinct shark species. By asking questions about shark evolution, comparing fossils and modern specimens, and their environments, we can hopefully understand more about these amazing animals.