Millions of years ago, the megalodon ruled the oceans – why did it disappear? | Today Headlines

When did the megalodon shark disappear and why? –Landon, 10

Imagine traveling in time and observing the oceans of 5 million years ago.

As you stand on an ancient shore, you see several small whales in the distance, gliding across the surface of an ancient sea.

Suddenly, and without warning, a huge creature emerges from the depths.

With its massive jaws, the monster crushes one of the whales and drags it down into the depths. Large body chunks are ripped off and swallowed whole. The rest of the whales disperse.

You have just witnessed the feeding time of the megalodon – officially known as Otodus megalodon – the biggest shark of all time.

About Megalodon

As a scientist who studies sharks and other ocean species, I am fascinated by the awesome marine predators that have come and gone over the eons.

This includes huge swimming reptiles like ichthyosaurs, plesiosaurs, and mosasaurs. These incredible predators lived in the age of the dinosaurs; megalodon would not appear for another 50 million years.

But when it arrived on the scene, around 15 to 20 million years ago, the megalodon must have been an incredible sight.

An adult individual weighed around 50 metric tons – that’s over 110,000 pounds (50,000 kilograms) – and was 50 to 60 feet (15 to 18 meters) tall. This animal was longer than a school bus and as heavy as a railroad car!

Its jaws were up to 10 feet (3 meters) wide, teeth up to 7 inches (17.8 centimeters) long, and bite force was 40,000 pounds per square inch (2,800 kilograms per square centimeter ).

Unsurprisingly, megalodons ate large prey. Scientists know this because they have found shards of megalodon teeth embedded in the bones of large marine animals. On the menu, in addition to whales: big fish, seals, sea lions, dolphins and other sharks.

The story continues

Are Scientists Sure Megalodon Is Extinct?

Internet rumors persist that modern megalodons exist – that they still swim in the oceans today.

But this is not true. Megalodons are gone. They went extinct about 3.5 million years ago.

And scientists know this because, again, they looked at teeth. All sharks, including megalodons, produce and eventually lose tens of thousands of teeth throughout their lives.

This means that many of these lost megalodon teeth are in fossil form. Some are found at the bottom of the ocean; others washed up on the shore.

But no one has ever found a megalodon tooth less than 3.5 million years old. This is one of the reasons why scientists believe that the megalodon disappeared then.

Additionally, megalodons spent much of their time relatively close to shore, a place where they easily found prey.

So if megalodons still existed, people would definitely have seen them. They were way too big to miss; we would have lots of photos and videos.

Why the megalodon disappeared

It’s probably not just one thing that led to the extinction of this incredible megapredator, but a complex mix of challenges.

First, the climate has changed dramatically. Global water temperature has dropped; this reduced the area where the megalodon, a warm-water shark, could thrive.

Second, because of climate change, entire species that megalodon fed on have disappeared forever.

At the same time, competitors have helped push megalodon into extinction, including the great white shark. Even though they were only a third the size of megalodons, the great whites likely ate some of the same prey.

Then there were killer sperm whales, a now extinct type of sperm whale. They grew as big as megalodons and had even bigger teeth. They were also warm-blooded; this meant that they benefited from an expanded habitat, since living in cold waters was not a problem.

Killer sperm whales probably traveled in groups, so they had an advantage when encountering a megalodon, which was probably hunting alone.

The cooling of the seas, the disappearance of prey and the competition, it was too much for the megalodon.

And that’s why you’ll never find a modern megalodon tooth.

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This article is republished from The Conversation, a nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Michael Heithaus, Florida International University.

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Michael Heithaus does not work for, consult, own stock, or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond his academic appointment.