Interrelation of radiocarbon ages from bone fractions in the Brazilian Intertropical Region

Abstract There is a consensus in the literature that radiocarbon dating performed on bioapatite often produces ages younger than dating performed on collagen. We propose a general regression that could be used to convert the bioapatite radiocarbon ages to the simulated ages on collagen in fossil samples worldwide. This general regression presents several good indices of quality, high correlation (R2 = 0.98), lower values of percent predicted error (%PE = 0.01), and standard error of the estimate (%SEE = 21.83), showing that it is a good tool, as the predicted values are similar to those observed. Using this regression, we converted the radiocarbon ages of bioapatite to the expected age from the collagen fraction made for several taxa from the Brazilian Intertropical Region (BIR) and suggest that these dates could be 1–7 cal ka BP older than previously thought.