Castlepook’s Deep-Time Femur
Archived: 17 September 2026
Abstract
At roughly 33,455 calibrated years BP, Ireland lay within the climatically unstable Marine Isotope Stage 3, when shifting ice, lower seas and altered coastlines created a cold, changing landscape. Later glaciation and submergence have erased much evidence, but Castlepook Cave in County Cork preserves Pleistocene fauna, including reindeer, mammoth, horse, giant deer and predators, demonstrating that parts of Ireland supported open-country ecosystems. A deeply incised reindeer femur may record fresh-bone processing with a stone tool and thus a brief Upper Palaeolithic human visit. However, uncertain dating and disturbed deposits preclude claims for settlement, hunting, identity or political and social institutions.