Megalodon teeth have always been key to understanding the ancient marine predator. Fossilized teeth are all that remain to prove the existence of these massive sharks, and the name megalodon is from the Greek for “big tooth.”
A new study, published in Earth and Planetary Science Letters, highlights the importance of the megalodon’s human-hand-sized teeth once again. Thanks to extracting and analyzing the traces of zinc left in the fossilized teeth, researchers now know that the megalodon’s diet was much broader than scientists once believed.
“Megalodon was by all means flexible enough to feed on marine mammals and large fish, from the top of the food pyramid as well as lower levels – depending on availability,” said Jeremy McCormack from the Department of Geosciences at Goethe University, in a press release.
Read More: The Massive Megalodon May Have Been Even Longer and Sleeker
What Did the Megalodon Eat?
Clocking in at 78 feet in length and weighing about twice as much as a semi truck, the megalodon was a big fish with a big appetite. It is suggested that a member of the Otodus shark family would require about 100,000 kilocalories per day to survive. Due to this extreme number, scientists have often assumed that the megalodon’s main source of calories came from whales.
This new study suggests that whales were not the only item on the megalodon’s daily menu and that these sharks were actually quite adaptable when it came to their food. The research team analyzed 18-million-year-old giant teeth that came from two fossil deposits in Sigmaringen and Passau. What they were looking for was the presence of zinc-66 and zinc-64, two isotopes commonly ingested with food.
Typically, the higher up in a food pyramid an animal is, the lower the presence of zinc. As they are oftentimes at the top of the food chain, species such as Otodus megalodon and Otodus chubutensis have a low ratio of zinc-66 to zinc-64 compared to species lower on the food chain.
“Sea bream, which fed on mussels, snails, and crustaceans, formed the lowest level of the food chain we studied,” said McCormack in the press release. “Smaller shark species such as requiem sharks and ancestors of today’s cetaceans, dolphins, and whales, were next. Larger sharks, such as sand tiger sharks, were further up the food pyramid, and at the top were giant sharks like Araloselachus cuspidatus and the Otodus sharks, which include megalodon.”
Surprisingly, the zinc levels in the megalodon teeth weren’t always that different from the zinc levels in species lower down the food chain. This result means that the commonly held scientific belief that megalodons focused their attention on eating large marine mammals may be incorrect.
Instead, McCormack refers to the megalodon as an “ecologically versatile generalist” that adapted to environmental and regional constraints that changed the availability and variety of their prey.
A New Method in Teeth Testing
Using the zinc content of fossilized teeth is a relatively new method of analysis, and the research team working on the megalodon couldn’t be happier with their results. The methods used in this study have not only been used for prehistoric shark and whale species but also modern-day shark species, and have even been used on herbivorous prehistoric rhinoceroses.
Overall, these new methods have begun to rewrite the history of megalodon’s eating habits and may help to explain more about why these giants of the food chain went extinct.
“[Determining zinc isotope ratios] gives us important insights into how the marine communities have changed over geologic time, but more importantly the fact that even ‘supercarnivores’ are not immune to extinction,” said Kenshu Shimada, a paleobiologist at DePaul University and a coauthor of this study, in the press release.
Read More: The Massive Megalodon Shark Was No Cold-Blood Killer
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As the marketing coordinator at Discover Magazine, Stephanie Edwards interacts with readers across Discover’s social media channels and writes digital content. Offline, she is a contract lecturer in English & Cultural Studies at Lakehead University, teaching courses on everything from professional communication to Taylor Swift, and received her graduate degrees in the same department from McMaster University. You can find more of her science writing in Lab Manager and her short fiction in anthologies and literary magazine across the horror genre.
