Scientists Reconstruct Megalodon’s Body – and It’s Not What You Think

For millions of years, Megalodon ruled the oceans. Growing to sizes that dwarfed today’s largest sharks, this icon is arguably the most talked-about extinct animal despite it disappearing from our planet a long time ago. Still, many mysteries surround this top predator. For example, what did they really look like? There has been long-standing belief that Megalodon was simply an oversized version of the great white shark. But a new study led by paleobiologist Kenshu Shimada of DePaul University, with contributions from 28 researchers worldwide, has reshaped how scientists think about this prehistoric giant. Published in Palaeontologia Electronica, the study challenges this idea; by analyzing body proportions from a wide range of modern and extinct sharks, the scientists suggest Megalodon had a sleeker body, more akin to today’s lemon shark (Negaprion brevirostris).

Formally known as Otodus megalodon, Megalodon lived between 15 and 3.6 million years ago, but its complete skeleton has never been found. Instead, scientists rely on its massive serrated teeth and fossilized vertebrae to estimate its size and shape. One of the most complete vertebral specimens, discovered in Belgium, measures 36 feet (11 meters) long, but it only represents the trunk of the shark — its head and tail were missing.

To estimate its full size, researchers examined the body proportions of 145 modern shark species and 20 extinct ones. Based on their findings, they determined that Megalodon’s head likely made up about 16.6% of its total body length, while its tail accounted for around 32.6%. Applying this to the Belgian specimen, the shark’s total length would have been roughly 54 feet (16.4 meters), with a 6-foot (1.8-meter) head and a 12-foot (3.6-meter) tail. However, another fossilized vertebrae from Denmark, measuring up to 9 inches (23 centimeters) across, suggest that some individuals may have been even larger. If those vertebrae belonged to the biggest Megalodons, their full body length could have reached an astonishing 80 feet (24.3 meters)… making them one of the largest sharks ever to exist! The study also estimated that a Megalodon of this size would have weighed around 94 tons.

So, what does this all mean? We already knew “the Meg” was a big shark, but this is the first evidence to show that it likely had a more slender body than the modern great white shark. While great whites are stocky and become even bulkier as they grow, large marine vertebrates like whale sharks (Rhincodon typus), basking sharks (Cetorhinus maximus), and even whales tend to have elongated, streamlined bodies. Why the difference in body shape? Well, stocky bodies create more drag, making it harder to move efficiently through water. The researchers believe that hydrodynamic constraints likely prevented great whites from growing beyond 23 feet (7 meters), while Megalodon’s more streamlined form allowed it to reach much larger sizes.

Beyond just body proportions, the study also explored Megalodon’s growth and lifestyle. Analysis of the fossilized vertebrae suggests that baby Megalodons were already massive at birth, measuring between 12 and 13 feet (3.6-3.9 meters) long. Like modern great whites, they likely practiced a form of in-utero cannibalism (embryos ate unfertilized eggs to fuel their early development). The study also found that Megalodon’s estimated cruising speed, based on the structure of its scales, was between 1.3 and 2.2 miles (2.1-3.5 kilometers) per hour, comparable to that of today’s great white sharks.

Perhaps one of the most intriguing implications of this research is what it reveals about Megalodon’s extinction. Despite their differences in body shape, the study supports the idea that the rise of the great white shark around 5 million years ago may have played a role in Megalodon’s decline. The two species likely competed for similar prey, and the more adaptable great white may have outcompeted its giant relative.

“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 Paleobiology professor Kenshu Shimada of DePaul University, who hopes a complete skeleton would be discovered someday to be able to put the interpretations to test. Until then, this research offers the best look yet at one of the most formidable predators to ever swim the seas.