Castlepook’s Scored Femur
Radiocarbon determinations are not calendar dates in themselves. They must be calibrated against changing atmospheric carbon levels, and at more than 30,000 years ago the resulting ranges can be broad or irregular. The current IntCal20 calibration framework extends to 55,000 calendar years before present, but it does not turn a single bone into an exact annual timestamp. The Castlepook femur should therefore be understood as belonging to a period around the mid-30th millennium before present, rather than as proof that butchery occurred in this particular numbered BCE year.