Millions of years ago, the ancient sperm whale fought with the predatory shark Megalodon. Scientists have found traces of this event in the territory of modern North Carolina.
According to the researchers, the marks from the attack, preserved in the form of indentations in the teeth of a sperm whale, are the first evidence in the fossil record that megalodon sharks fought with sperm whales.
“These giant sharks seemed to hunt whatever they wanted, and no marine animal was immune to the attacks of these giant sharks,” said lead author of the new study Stephen Godfrey, curator of paleontology at the Calvert Maritime Museum in Solomon Islands, Maryland. in an interview with Live Science.
The tooth is all that remains of the ancient sperm whale. The study’s co-founder, Norman Riker, an amateur fossil collector in Dowell, Maryland, discovered it in a modern phosphate mine in North Carolina in the 1970s. Then this mine was opened to collectors of fossils. Riker later donated the tooth to the Calvert Maritime Museum.
Researchers are not sure when exactly the fight between the shark and the whale took place. To get to the older, phosphate-rich strata, miners dumped sediment and dumped it nearby, where fossil gatherers could wash and study it, Godfrey said. Different layers of rocks that are deposited over time and therefore are used to date objects in these layers have mixed. Because of it, scientists don’t know if the tooth comes from older sedimentary strata that date it to the Miocene, 14 million years ago, or from younger fossil strata that date it to the Pliocene, about 5 million years ago.
In any case, the tooth belongs to the Neogene period (23–2.5 million years ago). During that time, the Earth’s climate was warmer than it is today, and as a result, there was less ice at the North and South Poles, so the sea level was higher. This is why “coastal North Carolina was covered by the vast, shallow waters of the Atlantic Ocean,” notes Godfrey. “These sea waters are teeming with marine life.”
According to Godfrey, the size and shape of the curved tooth, which is 11.6 cm long, indicates that it belongs to an extinct species of sperm whale. The researchers also concluded that this particular whale was small, only about 4 meters long. Godfrey noted that modern sperm whales can reach over 15 meters in length.
Three notches on the tooth indicate that it was bitten by either the shark Otodus chubutensis (which lived 28 to 13 million years ago) or its descendant Otodus megalodon (which existed 20 to 3.5 million years ago).
None of the other shark fossils known from phosphate mines have teeth large enough to leave these bite marks on a sperm whale’s tooth. Until now, bite marks from these giant sharks (over 18 m in length) have been found on other bones of extinct whales and dolphins, but never on the head or other bones of sperm whales.