Workers at the American Museum of Natural History fabricate and assemble a massive 27-foot-long, 10-foot-tall model of the ancient megalodon shark in New York City November 30. A new study shows that megalodons ate other predators. File Photo by John Angelillo/UPI | licensed photo
June 22 (UPI) — Considered the largest shark species to have ever lived, megalodons were big enough to eat just about any animal they wanted and may have been cannibals, scientists say in a study published Wednesday.
Princeton researchers say they have evidence that the shark species went extinct 3.5 million years ago, and their ancestors were at the very top of the food chain while they existed. They call it the highest “trophic level” of the food chain.
Megadolons and other megatooth sharks not only ate their fellow predators, they ate predator predators. There is even some evidence that megadolons were cannibals.
“Ocean food webs tend to be longer than the grass-deer-wolf food chain of land animals because you start with such small organisms,” lead author Emma Kast, now at the University of Cambridge, said in a press release.
“To reach the trophic levels that we measure in these megatooth sharks, we don’t just need to add one trophic level — one apex predator at the top of the marine food chain — we need to add several at the top of the modern marine food web,” Kast said.
The findings were published on Wednesday in the journal Scientific achievements.
Scientists found only fragmentary remains of megalodon sharks, but analysis of the teeth led them to the conclusion that the animal was up to 50 feet long. The largest predatory shark in existence, the great white, grows to an average of 15 feet.
Kast and her colleagues pinpointed the megalodon’s place in the prehistoric marine food web by measuring nitrogen isotope levels in its teeth. According to researchers, the more nitrogen-15 in the body, the higher its trophic level.
Organisms lower down the food chain are able to convert nitrogen from air or water into nitrogen in their bodies while larger organisms eat them. The higher up the food chain, the more the body excretes the lighter nitrogen-14 compared to the heavier nitrogen-15.
“The whole direction of my research team is to look for chemically fresh but physically protected organics, including nitrogen, in organisms from the distant geological past,” said Danny Sigman, professor of geological and geophysical sciences, and researcher Kasta. adviser.
“Teeth are engineered to be chemically and physically resistant so they can survive in highly chemically reactive oral environments and break down food that may have hard parts,” he added.
Sharks are constantly growing and losing teeth, unlike humans, which is why their teeth are among the most common fossil types in the ocean.
“And inside the teeth, there is a tiny amount of organic matter that was used to create tooth enamel — and is now trapped in that enamel,” Sigman said.
Researchers have developed a new method for extracting and measuring nitrogen-15 that involves the use of dental burs, chemicals and microbes that convert nitrogen into nitrous oxide, which can then be measured.
Sigman said his team and others are currently applying the technique to the study of mammalian and dinosaur teeth.