The ‘monster’, about 15 meters long and with teeth the size of a foot, ate everything it found, even to other predators and specimens of the same species.
About three million years ago, the megalodons, the largest sharks in history, sailed the seas of our planet. Although today it is impossible to accurately determine its size and shape, most estimates suggest that it was about 15 or 16 meters long and weighed about 45 tons.
One more piece of information on the importance of these ‘monsters’ for the prehistoric world has come from the recent study by Princeton University, USA, whose team claims to have evidence that the magalodon (‘Otodus megalodon’) and some of its ancestors were at the top rung of the prehistoric food chain, what scientists call the “trophic level”.
In fact, its trophic level is so high that scientists suggest that must have eaten other predators, and predators of predators, in a complicated food web, say the researchers in a statement published on the university’s website.
This monstrous predator represented a direct threat to all other species in the ocean, from fish to the largest mammals.
“We are used to think about the larger species. Blue whales, whale sharks, even elephants and diplodocus [a genus of dinosaur] as filter feeders or herbivores, not predators,” said Emma Kast, first author of the study published in the current issue of Science Advances.
“But the megalodon, like other megatoothed sharks, was a really huge carnivore that ate other predators and went extinct only a few million years ago,” he said.
To definitively establish megalodon’s position in the ocean’s prehistoric food chain, scientists performed an isotopic analysis of the few remaining fossil remains of the predator—its teeth—focusing on nitrogen-15.
The more of this nitrogen isotope there is in the body, the higher the animal’s position in the food chain.However, until now, no one has been able to measure exactly how much nitrogen- 15 contains the tooth enamel of ancient sharks.
The study showed that the Nitrogen-15 level of Miocene and Pliocene epoch megalodon steadily increased, positioning it in the food chain to occupy the highest position ever recorded in marine predators, both extinct and extant.
A possible explanation for the high values of nitrogen-15 is that the megalodons could have been cannibals, devouring members of their own species, and preying on young mammals that were still feeding on milk.