The first discovery of an in-situ megalodon tooth was made during a three-week expedition aboard Exploration Vessel (E/V) Nautilus. Researchers were piloting the remote-operated vehicle Hercules when they stumbled across the Otodus megalodon tooth at a depth of around 3,090 meters (9,842 feet) within the Pacific Remote Islands Marine National Monument.
The megalodon tooth is preserved only as the triangular crown but it is in remarkably good condition with the fine details of its serrated edge still visible. A jagged-edged tooth comes in handy when hunting for fleshy marine mammals like whales and dolphins, as a serrated edge makes for the ultimate cutting tool.
“This is an amazing find and is interesting in several aspects,” said Nicolas Straube, Associate Professor at the University Museum Bergen in Norway and co-author of the study, in a release emailed to IFLScience. “The fossil was discovered at a very remote deep-sea locality from which megalodon fossils are rarely documented. Further, its partial encapsulation with manganese suggests that fossil shark teeth are an ideal basis for manganese accumulation.”
The tooth is coated in parts with a crust of manganese, a chemical element that’s known to develop around fossil nuclei. Manganese nodules are objects of significant interest in the green battery revolution, as some companies believe harvesting abyssal plains for these lumps that are rich in rare metals could be a less damaging way to source the raw materials needed.
“90 percent of the world's exploration contracts for nodules are in the Clarion-Clipperton Zone, which represent less than half of 1 percent of the global seafloor,” The Metals Company PR and Media Manager Rory Usher told IFLScience.
“But this represents the largest source of manganese, nickel, and cobalt, anywhere on the planet and that dwarfs everything on land by many orders of magnitude. There are enough metals in situ at two of the sites that would satisfy the needs of 280 million cars, which represents every car in America, or a quarter of the world's vehicle fleet.”
However, like all explorative ideas, it’s not without its downsides.
The fierce tooth has sat on the seabed for at least 3.5 million years, write the researchers, and in that time may have served as food for a peculiar group of worms. The annelid (segmented worm) Osedax packardorum is known to bore into teeth to feed on dentin pulp, and it's possible the giant teeth of megalodon could’ve served as a hearty meal.
From one marine predator’s mouth to the seabed and a 3.5-million-year wait to be scooped up by a robot, this tooth sure has some stories to tell. Finding fossils in the deep sea might not be easy, but the researchers say it shows that it’s worth looking if we’re going to fill in the gaps in our knowledge of these poorly preserved animals.
“This fossil provides us with important insights into the distribution of megalodon,” said Jürgen Pollerspöck, researcher at the Bavarian State Collection of Zoology in Germany and co-author of the study. “The sample indicates that megalodon was not a purely coastal species and that this species migrated across ocean basins similar to many modern-day species such as the great white shark.”
The study is published in the journal Historical Biology.
An earlier version of this article was published in December 2023.