Modern Pacific rat bones

Modern Pacific rat bones

Some researchers, such as Atholl Anderson, have questioned whether rat bones yield reliable radiocarbon dates. It is suggested that not all contaminants are removed during chemical processing – a possible reason for the early dates (50–150 AD). Other explanations for the early dates are that the soils where the bones were deposited have contaminated them, or that the rats’ diet confuses the analysis. Research on both modern rat bones such as these, and on older bones from archaeological sites, has shown that in some circumstances old carbon in the environment can be absorbed by animals through their diet, and this might have influenced the analysis of the rat bones that were dated at 50–150. Dates on rat bones from a South Island cave site that yielded early (50–150) dates in the mid-1990s have not yet been duplicated by more recent dates (1250 or later) on rat bones.