BIRM-166 and Mammoth Cave
Archived: 17 September 2026
About 31,473 BCE, Ireland lay within the climatically unstable later Marine Isotope Stage 3, not a precisely datable historical year. Derryvree, County Fermanagh, preserves freshwater silts between glacial tills, dated broadly to 31,700–36,900 calibrated years BP, demonstrating ice-free, treeless wetland conditions. Castlepook Cave, County Cork, produced pre-Last Glacial Maximum bones of mammoth, reindeer, giant deer, predators and cold-adapted mammals, although its mixed deposits require caution. A possibly cut-marked reindeer femur suggests human activity, not settlement. Later ice advances destroyed earlier evidence. No political, cultural or economic history can be reconstructed; the surviving record chiefly documents changing environments, fauna and uncertainty.