Scientists have unearthed six new species of ancient sharks in Mammoth Cave National Park in Kentucky.
The paleontologists have dug up at least 40 distinct species of sharks over the course of a 10-month survey, Newsweek reported. Six of them are brand new to science. They range from big predators to tiny bottom-feeders.
Paleontologists believe the shark fossils are at least 325 to 340 million years old. That’s when the Mammoth Cave system’s limestones took shape, in the Late Paleozoic Era.
The team excavating the cave announced their findings this Wednesday, which was National Fossil Day. They first identified the fossils last November, WKU reported.
Paleontologist John-Paul Hodnett told WKU that no one has ever discovered the shark skeletal cartilage they found in Mammoth Cave anywhere else.
“We are literally just scratching the surface,” he said. “This information and the specimen are just pouring out. So it’s going to take time to process through all of it but we are excited from what we are seeing right off the bat.”
Their team found the new shark species in areas of the cave that are off-limits to the public. The scientists had to crawl along the cave floor to excavate the fossils.
Because shark skeletons are composed of cartilage, not bone, they often don’t survive the passage of years. There are only a few locations in the world where teams have found preserved shark cartilage, according to CBS News.
Cave Resource Management Specialist Rick Toomey, a vertebrate paleontologist at Mammoth Cave, told WKU that the cave has kept the fossils preserved for study.
“The fact that it’s here at the park keeps them from being exploited, being mined out, being sold as souvenirs,” he said. “So, the parks are very important for protecting these types of resources.”