Megalodon Mystery: 60-Foot-Long Shark Went Extinct Millions of Years Ago and Scientists Want to Know Why

Megalodon was the biggest shark ever to live. It could grow up to 60 feet in length and had 276 teeth, some of which were seven inches long. Its jaw was 11 feet wide—big enough to swallow two humans in one go.

It dominated as an apex predator of the oceans for about 20 million years. But 2.5 million years ago it went extinct—and scientists don't fully understand why. Sora Kim, from the University of California Merced, and colleagues have now been awarded over $200,000 to find out.

"There are many ideas about why the megalodon went extinct," Kim said in a statement. "Scientists have argued that changes in the megalodon's available prey base combined with climate change led to their demise. But these are just hypotheses. There have been no rigorous studies that demonstrate this conclusively."

GettyImages-92059370
Representative image: Great white shark. Dan Kitwood/Getty Images

The grant, from the National Science Foundation, will be used to solve the longstanding mystery. Studying the megalodon's disappearance is difficult as, like all sharks, their skeleton is made of cartilage and not bone. Cartilage does not fossilize, so unlike other ancient long lost creatures, there is little evidence for scientists to worth with. Instead, they must use the megalodon's teeth.

Over a shark's lifetime, it sheds thousands of teeth—and these teeth are extremely resilient to alteration. As a result, scientists can use them to track changes that take place over millions of years.

"Sharks are made of cartilage which does not preserve as well as bone," Kim told Newsweek. "On the other hand, shark teeth are abundant and have excellent preservation but are often not articulated, lost constantly (they do not necessarily represent where the animal died), and teeth can be resuspended and moved after deposition."

GettyImages-91285667
One of the world's largest set of shark jaws from the prehistoric species Carcharocles megalodon. Ethan Miller/Getty Images

Kim and her team hope to look at megalodon teeth from sites across the globe to look for clues about the predator's diet, habitat and physiology. "What did the meg eat? Could megalodon regulate its own body temperature? What was its environment like? And why did it go extinct? Isotope fingerprinting will provide more definitive answers to these questions," Kim said.

There were probably a number of contributing factors to the species' demise. "I think there was an interaction effect between climate and resource availability (i.e. prey) that likely led to their demise—but that is based on the correlation of timing rather than scientific evidence, which is what we're trying to establish with this project," she said.

Nothing like the megalodon could exist today—its size alone would make it extremely difficult for it to survive as a species. "But there is much of ocean life that is left to be discovered," Kim said. "For example, the megamouth shark was only discovered in 1976 and we still have very little information about its biology. There are new ocean discoveries made every year, which is why ocean conservation and management are so important—especially in light of the rapid and intense climate change."