Maguirebridge and Mammoth Cave
Archived: 20 September 2026
31,109 BCE is a modern chronological label, not a dateable Irish event. During Marine Isotope Stage 3, Ireland experienced unstable cold conditions before maximum glaciation. Derryvree, County Fermanagh, preserves freshwater sediments between tills, indicating treeless wetlands with grasses, sedges, herbs, juniper, insects and shallow pools during an ice-free interval. Castlepook Cave, County Cork, yielded mammoth, reindeer, hyaena and other cold-adapted fauna, demonstrating open grazing country and changing connections to north-west Europe. A cut-marked reindeer bone may indicate human carcass processing about 33,000 years ago, but cannot prove settlement. Subsequent ice expansion destroyed or buried much earlier evidence across the island.