The extinct superpredator megalodon was big enough to eat orcas, scientists say

Workers assemble a model of a megalodon shark at the American Museum of Natural History, in New York, Tuesday, Nov. 30, 2021. (AP Photo/Richard Drew)

Faster than any shark alive today and big enough to eat an orca in just five bites: A new study suggests the extinct shark known as a megalodon was an even more impressive superpredator than scientists realized before.

The Otodus megalodon, the inspiration behind the 2018 film "The Meg," lived more than 23 million years ago. Fossils of the extinct giant are hard to come by: While there are plenty of fossilized shark teeth, their bodies mainly consist of cartilage rather than bones, and are rarely preserved.

A research team led by Jack Cooper, a paleobiologist at Swansea University, set out to use 3D modeling from a rare and exceptionally well-preserved megalodon spinal column to extrapolate information about the shark's movement and behavior. Their research was published in Science Advances Wednesday.

"We estimate that an adult O. megalodon could cruise at faster absolute speeds than any shark species today and fully consume prey the size of modern apex predators," wrote the researchers.

Most of what we know about megalodons come from scientific inferences: Scientists have estimated the extinct sharks could be as long as 65 feet through a comparison with great white sharks, thought of as their "best available ecological analog," since they both occupy the top rung in the food chain, according to the article.

The researchers used a megalodon vertebral column from Belgium, a tooth from the United States, and the chondrocranium -- the cartilaginous equivalent of a skull -- from a great white shark to build their 3D skeleton. Then they used a full-body scan of a great white shark to estimate how flesh would sit on the megalodon's skeleton.

With a complete 3D rendering, they came up with estimates for the volume and body mass of the shark's whole body. By comparing the figures to the size of modern sharks, they estimated the shark's swimming speed, stomach value, calorie needs, and prey encounter rates.

The megalodon they modeled would have been almost 16 metres, or 52 feet, long. It weighed around 61,560 kilograms, or 135,717 pounds, according to their estimates.

They estimated the megalodon would have been able to devour prey the size of orca whales -- which can be up to 26 feet long and weigh over 8,000 pounds -- in just five bites.

Prey the size of a modern humpback whale would have been too big for a megalodon to eat in full, according to the researchers. Eating large prey may have given the megalodon a competitive edge over other predators. Eating large amounts at a time would have also allowed them to travel great distances without eating again, much like modern great white sharks.

An adult megalodon would have needed to eat a whopping 98,175 calories per day, 20 times higher than an adult great white shark. They could have met their energetic needs by eating around 31.9 kilograms of shark muscle, according to the researchers' estimates.

The megalodon was also faster than any shark alive, with a theoretical average cruising speed of around 3.1 mph, according to the study. This speed would have allowed it to encounter more prey, helping it meet its massive caloric demands.

Overall, the data extrapolated from the 3D model paints the portrait of a "transoceanic superpredator," say the researchers.

Luckily, today's orcas don't have to worry about running into the massive shark. The megalodon went extinct around 3.6 million years ago, according to the United Kingdom's Natural History Museum, for reasons scientists are still trying to understand.