Age distributions of hominid samples at Atapuerca (SH) and Krapina could indicate accumulation by catastrophe

Abstract

Age distributions of the Atapuerca (SH) (MNI=32) and Krapina (average MNI=23·5) hominid assemblages differ markedly from that of the pooled Neanderthals. Three out of six statistical tests imply both assemblages resulted from catastrophe while for the remaining three no decision can be made due to the very small size of the age samples in the age-class 5–14 years. It is improbable that the human bones accumulation be the result of an attritional mortality via, either a regular lion predation, or a kind of primitive cemetery. However, there is either a marked underrepresentation of the individuals aged 5–14 years or an overrepresentation of those aged 15–24 years, along with an underrepresentation of the younger (below 5 years) and older individuals (25 years and above). The mortality distribution corresponds neither to a shortage nor an epidemic mortality profile. The curious age distribution of both hominid samples may be best explained as a result of a demographic crisis of a local group for a meta-population in nature, caused by severe environmental fluctuation.