Scientists have long believed that the colossal prehistoric shark Otodus megalodon hunted primarily large marine mammals like whales. But new research suggests this oceanic giant was far more versatile in its feeding habits than previously thought.
A study published in Earth and Planetary Science Letters reveals that megalodon may have been an opportunistic predator, consuming a wide range of prey to meet its extraordinary energy demands—an estimated 100,000 calories per day.
“When available, it would probably have fed on large prey items, but when not available, it was flexible enough to feed also on smaller animals,” said lead author Jeremy McCormack, a geoscientist at Goethe University in Frankfurt, Germany.
The team conducted a geochemical analysis of fossilized megalodon teeth and compared them with those of other marine animals from the same era. The findings reveal that megalodon’s diet varied regionally and included not just large prey, but also smaller animals, possibly even other sharks and bony fish.
These new insights came from examining zinc isotopes in the shark’s tooth enamel. Zinc, an essential mineral acquired through diet, leaves behind isotope signatures that can indicate an animal’s position in the food chain. The study found that while megalodon occupied a top-tier predator role, its isotope ratios showed a broader dietary range than expected—suggesting it fed across multiple levels of the food web.
The research also indicates that megalodon shared its apex predator status with other large carnivorous sharks of the time, such as Otodus chubutensis and Araloselachus cuspidatus. This challenges the long-standing view of megalodon as the sole ruler of ancient oceans.
“This shark was clearly a fierce apex predator, but not a specialist. It was a generalist feeder that could prey on virtually anything around it,” McCormack noted.
The findings may also support the theory that megalodon’s extinction was influenced by the rise of the great white shark (Carcharodon carcharias). The modern great white, which begins life eating fish before shifting to marine mammals, may have outcompeted the larger but potentially less agile megalodon.
“Our study strengthens the idea that dietary overlap with the emerging great white could have contributed to megalodon’s demise,” said coauthor Kenshu Shimada, a paleobiologist at DePaul University.
The research further supports growing evidence that megalodon was not just an enlarged version of the great white shark. According to Alberto Collareta of the University of Pisa, who was not involved in the study, megalodon had distinct traits in size, shape, and biology.
“We’ve moved away from viewing megalodon as an inflated great white,” Collareta explained. “The Miocene ecosystems these sharks lived in weren’t dramatically different from today’s oceans, but they featured completely extinct players like the megatooth sharks.”
Despite the advances, scientists caution that much about megalodon remains unknown due to limited fossil evidence. With only teeth, some vertebrae, and a few scales to study, the complete picture of this ancient predator is still emerging.
“What I’d really love to see from the fossil record is a complete Meg skeleton,” Collareta added. “Let’s hope the past still has some surprises in store.”
