Mammoth Cave National Park: Paleontological resource inventory (sensitive version)

Mammoth Cave National Park (MACA) in south-central Kentucky protects one of the most famous and extensive cave systems in the world. Fossils, both in the bedrock of the cave system and as much more recent remains that date to the cave era, have been reported since at least the first half of the 19th century, but have rarely been a focus of investigation. In 2019, following a report of shark fossils in the wall of a cave passage, a team of MACA staff and volunteers, members of the National Park Service (NPS) Paleontology Program, and paleontological specialists from outside the NPS began a paleontological resource inventory at the park. This inventory was established to document the scope, significance, temporal and geospatial distribution, and management issues associated with these non-renewable resources at the park. The Mammoth Cave System and other caves at MACA formed in bedrock that dates to the Middle to Late Mississippian, approximately 335 to 325 million years ago. At this time, the future area of MACA was submerged beneath a continental sea. The seafloor was carpeted with corals, crinoids, and other marine invertebrates. A diverse array of cephalopods, cartilaginous fishes, ray-finned fishes, and other animals swam above them. Occasionally the sea receded and was replaced by coastal lands that supported abundant plants. The resulting terrestrial beds, deposited as late as the early Pennsylvanian (approximately 320 million years ago), are not soluble like the marine beds and now cap the caves and ridges. Both marine and terrestrial beds preserve abundant fossils. Hundreds of millions of years later, passages began to form in the ancient Mississippian marine carbonate rocks, and when these became connected to the surface, organisms from the outside began to enter or fall into the developing cave system, sometimes to be preserved as fossils. Fossils from the Quaternary (2.58 million years ago to the present) represent organisms that inhabited the area during the shifting climate of the Ice Age, including extinct animals such as mastodons, saber-toothed cats, and short-faced bears. After several years of site visits, photography and photogrammetry, specimen collection and preparation, literature and archival research, expert consultation, and other study, documentation, and description, MACA can stake a claim to being one of the most paleontologically significant units in the NPS. This report summarizes the findings of the inventory team and will help future investigators understand and manage the park’s paleontological resources.