New Study Reveals Megalodon Was Slim, Not Stocky—And Why That Matters todayheadline

The prehistoric megalodon shark—a creature that has captured our imagination in countless films and books—likely looked nothing like the bulky great white shark it’s often portrayed as, according to groundbreaking new research. Instead, scientists now believe this ancient ocean predator had a more streamlined body shape, a revelation that helps explain how it achieved its colossal size.

A comprehensive study led by DePaul University paleobiology professor Kenshu Shimada, along with 28 other experts from nine countries, has challenged long-held assumptions about the appearance and biology of Otodus megalodon, which ruled the oceans from 15 to 3.6 million years ago.

The largest individuals may have reached a staggering 24.3 meters (80 feet) in length—about the size of a bowling lane—and weighed approximately 94 tons, according to findings published in the journal “Palaeontologia Electronica.”

“The length of 24.3 meters is currently the largest possible reasonable estimate for O. megalodon that can be justified based on science and the present fossil record,” said Shimada, who works in DePaul University’s Department of Environmental Science and Studies and Department of Biological Sciences.

Rethinking the Ancient Predator

Despite its fame, megalodon remains surprisingly mysterious to science. No complete skeleton has ever been found, leaving paleontologists to piece together its appearance primarily from fossilized teeth, vertebrae, and scales.

Movies like “The Meg” typically depict the prehistoric shark as essentially a supersized version of today’s great white shark. However, the research team’s analysis suggests this portrayal is fundamentally incorrect.

The scientists examined body proportions across 145 modern and 20 extinct shark species to determine how megalodon’s body parts likely related to one another. Their work focused on a well-studied fossilized vertebral column from Belgium measuring about 11 meters (36 feet).

By analyzing this specimen and comparing it with other sharks, they calculated that megalodon’s head and tail would have occupied about 16.6% and 32.6% of its total body length, respectively. For the Belgian specimen, this translates to a head measuring approximately 1.8 meters (6 feet) and a tail spanning 3.6 meters (12 feet), resulting in a total estimated length of 16.4 meters (54 feet).

Form Follows Function

Perhaps the most surprising finding is that megalodon likely resembled the modern lemon shark—which has a more slender, streamlined body—rather than the stockier great white shark.

“Our new study has solidified the idea that O. megalodon was not merely a gigantic version of the modern-day great white shark, supporting our previous study,” said Phillip Sternes, one of Shimada’s former master’s students who is now an educator at SeaWorld San Diego.

This revelation helps explain why certain marine vertebrates can achieve gigantic sizes while others cannot. The researchers observed that today’s largest sharks—the whale shark and basking shark—as well as whales, all have relatively slender bodies. This body type is hydrodynamically more efficient for swimming at extreme sizes.

In contrast, the great white shark, with its stockier build that becomes even more pronounced as it grows, faces hydrodynamic constraints that limit its maximum size to around 7 meters (23 feet).

“What sets our study apart from all previous papers on body size and shape estimates of O. megalodon is the use of a completely new approach that does not rely solely on the modern great white shark,” added Jake Wood, another of Shimada’s former students who is now pursuing doctoral studies at Florida Atlantic University.

Life and Death of a Giant

The study also provided new insights into megalodon’s life cycle. Growth patterns in vertebral specimens suggest the sharks gave birth to live young measuring about 3.6-3.9 meters (12-13 feet) long—already larger than most adult great whites today. Embryos likely nourished themselves through oophagy, or egg-eating behavior.

Based on scale morphology, the researchers estimated megalodon’s cruising speed at 2.1-3.5 kilometers (1.3-2.2 miles) per hour, comparable to today’s great white shark despite its much larger size.

The fossil record also reinforces the theory that competition from the emerging great white shark approximately 5 million years ago likely contributed to megalodon’s eventual extinction.

“Many interpretations we made are still tentative, but they are data-driven and will serve as reasonable reference points for future studies on the biology of O. megalodon,” said Shimada, who hopes a complete skeleton will someday be discovered to test these interpretations.

This research not only reshapes our understanding of one of history’s most formidable predators but also provides valuable insights into the biomechanical constraints that govern gigantism in aquatic vertebrates—a puzzle that has long intrigued marine biologists and paleontologists alike.

For now, moviegoers may need to adjust their mental image of the prehistoric sea monster. Rather than a bulky behemoth, evidence suggests megalodon was a sleek, streamlined giant—an adaptation that allowed it to reach dimensions that continue to awe us millions of years after its disappearance from the world’s oceans.