Scientists have found remains of three animals at the mouth of an unexplored cave in South Dakota's Black Hills, along with other bones dating back almost 11,000 years, and are now on a mission to unearth the cave's opening, the AP reports. What they hope to find: more hints about how the climate has changed in the region during the past few thousand years. The team led by East Tennessee State University's Jim Mead—with assistance from workers at Wind Cave National Park, the University of Maine, and two museums, per KCSR—is already lugging out bags of sediment and bones for analysis from Persistence Cave. But the National Park Service has kept the cave under wraps since 2004 to keep amateur spelunkers away, and still won't say where the cave is located.
At issue are the remains of three species never before seen in the region: the pine marten, pika, and now-extinct platygonus. The rodent-like pika, for example, still exists in North America's colder, mountainous areas, an indication that the Black Hills' climate may have once been quite different. "What has changed to push [the pika] into Wyoming but not be in the Black Hills?" says Mead. They plan to compare their findings with fossils discovered at the nearby Mammoth Site in Hot Springs, SD, "to understand essentially the Ice Age environmental change through time," says Mead. What's more, a park employee believes Persistence Cave may be secretly joined to the park's famous "breathing" Wind Cave through an undiscovered passage. (A cave in Israel recently turned up artifacts from Alexander the Great's time.)