The gigantic Megalodon shark was much larger than previously thought

For years, the megalodon has been imagined as a monstrous version of the great white shark. Depictions in movies and documentaries show a stocky, torpedo-shaped predator, built for speed and power. However, recent research challenges this long-held perception.

A new study suggests that the megalodon may have had a much longer, more slender body, resembling a lemon shark or even a massive whale rather than an oversized great white.

Determining the size of an extinct creature is challenging, especially when only fragments remain. Unlike dinosaurs, whose skeletons can often be reconstructed from fossilized bones, megalodons are mostly known from their gigantic teeth—some measuring over 16 centimeters.

A few vertebrae and cartilage fragments have been discovered, but no complete skeleton exists. This has made it difficult for scientists to accurately estimate the shark’s true size.

Previous estimates relied on comparisons with great white sharks, which were once thought to be megalodon’s closest living relatives. By scaling up white shark proportions, researchers previously estimated that the megalodon reached lengths of 15 to 20 meters and weighed up to 103 metric tons. However, some scientists have questioned whether the great white is truly a suitable comparison.

Phillip Sternes, a shark biologist from the University of California, Riverside, led a team that re-evaluated these assumptions. Instead of relying solely on tooth size, they examined megalodon vertebrae and compared them to over 100 living and extinct shark species.

Their findings, published in Palaeontologia Electronica, suggest that previous estimates underestimated the shark’s true proportions. According to their analysis, the megalodon may have grown to nearly 80 feet (24 meters) in length, with a weight of around 94 metric tons—comparable to a large blue whale.

The research team’s biggest revelation was that megalodon likely had a body shape more like a lemon shark than a great white. Unlike the bulky, powerfully built great white, the lemon shark has a longer, more streamlined body that allows for efficient movement. This means that rather than being a high-speed predator relying on bursts of energy, megalodon may have been a long-distance cruiser, capable of covering vast stretches of ocean with minimal effort.

“This study provides the most robust analysis yet of megalodon’s body size and shape,” Sternes explained. “Rather than resembling an oversized great white shark, it was actually more like an enormous lemon shark, with a more slender, elongated body. That shape makes a lot more sense for moving efficiently through water.”

The shape of an animal’s body has a direct impact on how it moves. Olympic swimmers, airplanes, and even marine predators must minimize drag to travel efficiently. A stocky, muscular body may allow for short bursts of speed, but for an animal the size of megalodon, a streamlined shape would have been crucial for survival.

“You lead with your head when you swim because it’s more efficient than leading with your stomach,” said UCR biologist Tim Higham, who contributed insights on movement. “Similarly, evolution moves toward efficiency, much of the time.”

One of the most intriguing findings of the study is that megalodon pups were already massive at birth. Newborns may have been as long as 13 feet—about the size of an adult great white shark. This suggests they were already capable predators from a young age, likely hunting marine mammals soon after birth.

“This research not only refines our understanding of what megalodon looked like, but it also provides a framework for studying how size influences movement in marine animals,” Sternes said.

The study also adds to the broader understanding of gigantism in marine animals. Large aquatic predators—from extinct marine reptiles to today’s whales—tend to evolve within certain size and shape constraints.

The physics of swimming impose limits on how stocky or stretched out a massive predator can be. Too bulky, and the energy costs of movement become too high. Too slender, and the predator loses strength and power.

“The physics of swimming limit how stocky or stretched out a massive predator can be,” Higham said. “Gigantism isn’t just about getting bigger—it’s about evolving the right body to survive at that scale.”

The megalodon may have been one of the most extreme examples of this evolutionary balance. Its streamlined body allowed it to move efficiently through the ocean, conserving energy while remaining an apex predator. This new understanding of megalodon’s body shape also raises questions about its hunting strategies. Rather than relying on bursts of speed like the great white, it may have ambushed its prey in open water, using its massive size to overwhelm large marine mammals.

For over a century, megalodon has been reconstructed based on assumptions about its relationship to great white sharks. But this study suggests that its evolutionary path may have been quite different. The findings challenge not only how scientists envision this ancient predator but also how they study extinct species in general.

By looking beyond the great white shark and examining a broader range of living and extinct species, the researchers have created a more accurate picture of one of history’s largest carnivores. Their findings reshape our understanding of how massive marine predators evolved and highlight the importance of reconsidering old assumptions.

“Evolution favors efficiency,” Sternes said. “And megalodon may have been one of the most efficient giant predators the ocean has ever seen.”

Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.

Like these kind of feel good stories? Get The Brighter Side of News' newsletter.