The scientists were surprised to find traces of the giant fossil shark head from 330 million years ago in the cave walls in Kentucky.
The remains of this ancient animal were found in Mammoth Cave National Park – the world’s longest cave system, according to the National Parks Authority.
The shark fossil, which was discovered by scientists who were investigating the cave system, is thought to be up to about 330 million years old, according to John-Paul Hodnett, a paleontologist and program coordinator at Dinosaur Park in Maryland.
The scientists sent Hodnett photos of the findings so he could help identify them. He was able to identify most of the fossils, but what got him “really excited” was to see a number of shark teeth associated with large sections of fossilized cartilage.
“This was kind of a big deal,” he said. “It suggested there might have been a shark skeleton in the cave.”
Shark has skeletons made of cartilage, which is not fossilized, so it is rarely kept intact. Preserved cartilage can only be found in very few parts of the world.
On the other hand, shark teeth are among the fossils commonly found around the planet because these animals replace their teeth regularly.
Hodnett eventually visited the park to examine the fossils, and while he did not uncover a full skeleton, he found parts of a head that belonged to a prehistoric shark, which he said was the size of a modern great white shark.
Based on what was exposed in the cave wall, he identified a 2 ½-foot-long lower jaw, teeth, and other cartilage belonging to this one large shark and around 100 extremely detailed teeth of other shark species.
“What we saw in the cave was amazing because just from the shape of the jaw we’ll be able to find out more about how this species lived and we’ll be able to fit it in the shark family tree more accurately,” Hodnett said.
The team determined that the shark belonged to a species called Saivodus striatus that lived some 330 million years ago during the Late Mississippian geological period.
Most shark fossils discovered by researchers come from a layer of rock extending from Missouri to Virginia. However, this is the first time the presence of sharks has been recorded.