Latest news with #OtodusMegalodon
Forbes
26-05-2025
- Science
- Forbes
Largest Shark To Ever Swim In Our Oceans Was Not A Picky Eater
Fossil O. megalodon tooth compared to a recent-day great white shark tooth. Otodus megalodon, the largest shark to ever swim in our planet's oceans, still inhabited the sea up to around 3.6 million years ago. Despite its fame in pop-culture, surprisingly little is known about the anatomy and behavior of this species. Sharks have only a cartilaginous skeleton that quickly decays after death, only their hard teeth survive the long and arduous fossilization process. Based on the fragmentary remains, length estimates for a full-grown O. megalodon range from 50 to 100 feet (15-30 meters). Special evolutionary adaptions including warm-bloodedness (an organism's ability to maintain a relatively constant internal temperature) and giving birth to fully-developed newborns likely led to this gigantism. The living animal required around 100,000 kilocalories per day. Scientists widely assumed that O. megalodon's main calorie intake was in the form of whales, large preys providing also a high-caloric input thanks to their fat reserves. However O. megalodon was not a picky eater, says Dr. Jeremy McCormack from the Department of Geosciences at Goethe University Frankfurt. McCormack and colleagues extracted zinc from the fossil teeth, an element that occurs in isotopes of different weights. Zinc is ingested with food, but the specific isotopes preserved in muscles, organs and skeletal tissues depend on the animal's place in the food chain. The tissue of large fish that eat smaller fish absorbs significantly less zinc-66, and predatory animal which, in turn, hunt them for food absorb even less. "Since we don't know how the ratio of the two zinc isotopes at the bottom of the food pyramid was at that time, we compared the teeth of various prehistoric and extant shark species with each other and with other animal species. This enabled us to gain an impression of predator-prey relationships," explains McCormack. The fossils they used for their study mostly came from marine deposits in Sigmaringen and Passau (Germany). Analyzing the zinc isotopes in the fossil remains of different species, they reconstructed the food chain as it appeared 18 million years ago. "Sea bream, which fed on mussels, snails and crustaceans, formed the lowest level of the food chain we studied. 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," explains McCormack. The zinc signal in fossil O. megalodon teeth is more variable than expected. 'Our study tends rather to draw a picture of megalodon as an ecologically versatile generalist; … 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.' "It 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," adds Kenshu Shimada, a paleobiologist at DePaul University in Chicago, U.S., and a coauthor of the new study. The study,"Miocene marine vertebrate trophic ecology reveals megatooth sharks as opportunistic supercarnivores," was published in the journal Earth and Planetary Science Letters. Additional material and interviews provided by Sadie Harley and Robert Egan, Goethe University Frankfurt am Main.
Newsweek
26-05-2025
- Science
- Newsweek
Megalodon: Largest Ever Shark's Diet Surprises Geoscientists
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. A new study has uncovered surprising insights into the feeding habits of the largest predatory fish to ever roam the Earth's oceans, challenging long-standing assumptions about the prehistoric predator. For centuries, scientists believed that Otodus megalodon hunted exclusively at the top off the food chain, but a new study led by Jeremy McCormack from the Department of Geosciences at Goethe University Frankfurt found that its diet was far more flexible than previously thought. Longer than a truck with a trailer (reaching up to almost 79 feet long) and weighting almost twice as much, Megalodon, ruled the oceans between 20–3 million years ago, frequently on the hunt for prey to satisfy its astonishing 100,000 kilocalories-per-day nutritional demand. Its massive jaws were filled with triangular teeth, each the size of a hand, and its deadly bite had the force of an industrial hydraulic press, leaving no hope for any creature crossing its path. It was thanks to its fossilized teeth that McCormack, in collaboration with other scientists from Germany, France, Austria and the US, were able to discover the apex predator's unusual dietary habits. A stock image shows a 3D illustration of the Otodus Megalodon, the largest predatory fish that has ever existed. A stock image shows a 3D illustration of the Otodus Megalodon, the largest predatory fish that has ever existed. getty images By analyzing the levels of zinc in the fossils, the study found that while Megalodon did surely feast on whales and dolphins whenever it had a chance, the shark adjusted its diet based on availability of the prey. Zinc occurs in atomic variants (isotopes) of different weights, and is ingested with food. Less of the heavier isotope zinc-66 than the lighter isotope zinc-64 is stored in muscles and organs. Predatory fish absorb significantly less zinc-66 and those at the top of the food chain absorb even less. "Since we don't know how the ratio of the two zinc isotopes at the bottom of the food pyramid was at that time, we compared the teeth of various prehistoric and extant shark species with each other and with other animal species. This enabled us to gain an impression of predator–prey relationships 18 million years ago," explained McCormack in a statement. Sea bream—a fish which fed on mussels, snails and crustaceans—formed the lowest level of the food chain, followed by smaller shark species such as requiem sharks and the ancestors of today's cetaceans, dolphins and whales. 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 shark genus, which includes Megalodon. Results of the study showed that the levels of zinc found in the Megalodon couldn't be sharply differentiated from the lower levels of the pyramid, suggesting that the largest shark that ever lived was flexible enough to feed on both marine mammals and large fish from the top of the food pyramid as well as lower levels. Jeremy McCormack at the mass spectrometer, which is used to determine the zinc isotope ratio. This ratio provides information about the diet of Otodus megalodon. Photo: Uwe Dettmar for Goethe University Jeremy McCormack at the mass spectrometer, which is used to determine the zinc isotope ratio. This ratio provides information about the diet of Otodus megalodon. Photo: Uwe Dettmar for Goethe University Uwe Dettmar, Goethe University "Our study tends rather to draw a picture of megalodon as an ecologically versatile generalist," McCormack added. The shark's diet also greatly varied depending on its location and regional availability of prey. The teeth used for the study mostly came from 18-million-year-old fossil deposits in the German cities of Sigmaringen and Passau—and sharks in these locations showed different food habits. The creatures from Passau fed more on prey from lower levels of the food pyramid, probably due to lack of bigger fish in the area. McCormack said that the new method of determining tooth zinc isotope ratios has once proven to be a valuable instrument for paleoecological reconstructions. Kenshu Shimada, paleobiologist at DePaul University in Chicago, USA, and coauthor of the study added: "It 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." Do you have a tip on a science story that Newsweek should be covering? Do you have a question about Megalodon? Let us know via science@
