Megalodon was nothing like a giant great white shark

Megalodon, the ancient shark often depicted as a super-sized great white, was in fact a rather different beast, according to a new analysis of fossil evidence. The fearsome predator was longer, more slender and hunted in a different way, a team of shark scientists has concluded.

Best known from its depiction in the Meg film franchise, Otodus megalodon went extinct around 3.5 million years ago. It was one of the largest marine predators to have ever lived, but no complete skeleton has ever been found, so we can’t be sure exactly how large it was.

A 2022 study by Jack Cooper at Swansea University, UK, and his colleagues reconstructed the animal based on a partial fossilised skeleton known as IRSNB P 9893, housed at the Royal Belgian Institute of Natural Sciences in Brussels. The results showed a stocky, powerful shark built for bursts of speed to attack prey, similar to the great white shark (Carcharodon carcharias) of today – but, at 15.9 metres, about three times as long.

Charles Underwood at Birkbeck, University of London, says that study made “tenuous assumptions” about the size of megalodon based largely on it having similar teeth to a great white, though megalodon’s are much larger. He is part of a group of 26 shark experts who aim to set the record straight with a new study.

According to Underwood, Cooper’s team didn’t realise how incomplete the partial skeleton was. Its vertebrae lack the typical tapering in size towards both the tail and the head of the shark, he says, indicating that many of them are missing.

The team behind the new study says the strength of the spinal column suggests a more slender body shape than that of a great white, as a shark of megalodon’s length shaped like a great white would be overly cumbersome.

“It would almost certainly not be feeding like modern great whites,” says Underwood. “It wouldn’t be hovering over the sea floor waiting for a whale to move above it and then slamming into it from below, basically shredding it. It would involve more straight pursuit, a longer pursuit, less of an ambush predator. Because it doesn’t have the top speed; it doesn’t have the acceleration.”

Based on another partial fossil, the biggest known specimen of megalodon was estimated to be 20 metres long. Underwood thinks it might actually have been 20 per cent longer, making it 24 metres long.

But Cooper dismisses the new study as too simplistic and stands by his reconstruction of a shorter, stockier megalodon. “The long and short of it is that no matter which hypothesis you support about its body shape, it was a very big shark,” he says. “Of course, a complete skeleton would go a long way to helping us find out more. But I also don’t think we should assume this would settle all debates on this very charismatic animal.”

The chances of finding a complete, well-preserved specimen may be slim, however. Eva Stewart at the University of Southampton, UK, who wasn’t involved in the research, says she has recovered many megalodon teeth while scouring for new live species – but has seen no sign of a more complete specimen.

“I think it’s just the rest of the skeleton doesn’t seem to be well preserved,” she says. “With the megalodon, there’s not actually much fossil evidence at all.”