The megalodon has long been imagined as an enormous great white shark, but new research suggests that perception is all wrong. The study finds the prehistoric hunter had a much longer body—closer in shape to a lemon shark or even a large whale.
The study team, which included researchers from University of California, Riverside and across the globe, used a novel approach to estimate the shark's total body length, moving beyond traditional methods that rely primarily on tooth size. By examining megalodon's vertebral column and comparing it to over 100 species of living and extinct sharks, they determined a more accurate proportion for the head, body, and tail.
The findings, published today in the journal Palaeontologia Electronica, suggest the prehistoric predator may have reached about 80 feet, or about two school buses in length. It also likely weighed an estimated 94 tons, comparable to a large blue whale, but with a body designed for energy-efficient cruising rather than continuous high-speed pursuit.
"This study provides the most robust analysis yet of megalodon's body size and shape," said Phillip Sternes, a shark biologist who completed his Ph.D. at UCR. "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."
Great white sharks have a stocky, torpedo-shaped body built for bursts of speed, with a broad midsection that tapers sharply toward the tail. In contrast, lemon sharks have a leaner, more uniform body shape, with a less pronounced taper. Their longer, more cylindrical build allows for smoother, more energy-efficient swimming. If megalodon had a body structure more like a lemon shark, as this study suggests, it would have looked much sleeker than the bulky predator often depicted in popular media.
Sharks, like airplanes or Olympic swimmers, must minimize drag to move smoothly and easily.
"You lead with your head when you swim because it's more efficient than leading with your stomach," said Tim Higham, UCR biologist who contributed insights to the study on how animals move through water. "Similarly, evolution moves toward efficiency, much of the time."
The study highlights how large aquatic animals including sharks, whales, or even extinct marine reptiles, follow similar patterns when it comes to body proportions. "The physics of swimming limit how stocky or stretched out a massive predator can be," Higham said.
The research also sheds light on megalodon's swimming capabilities. While debates have raged over whether it was a high-speed predator or a slower, cruising hunter, the new findings suggest a balance. The shark likely swam at moderate speeds, with the ability to burst forward when attacking prey. Given its sheer size and energy demands, constant high-speed swimming wouldn't have been efficient.
The study also indicates that as a newborn, a megalodon could have been nearly 13 feet long, roughly the size of an adult great white shark. "It is entirely possible that megalodon pups were already taking down marine mammals shortly after being born," Sternes said.
A key breakthrough of this study was identifying the lemon shark as the best living analog for megalodon's proportions. Unlike the great white, lemon sharks have a more elongated body. When the researchers scaled up the proportions of a lemon shark to megalodon's estimated length, it was a near-perfect match.
"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.
Beyond reshaping our understanding of megalodon, the study offers insight into why only certain animals can evolve to massive sizes.
"Gigantism isn't just about getting bigger—it's about evolving the right body to survive at that scale," Sternes said. "And megalodon may have been one of the most extreme examples of that."
