Recovery of skeletal remains from archaeological burial site: what is the rate of missing bones?

The study of human skeletons in archaeology is useful for understanding the demography and pathology of ancient populations. Incomplete recovery can severely compromise this reconstruction. The loss of a single phalanx, for example, can hinder the diagnosis of diseases such as leprosy or sharp force injury, and compromise the anthropological and pathological study. But how much of the skeleton is really lost at excavation? Very little literature exists on this. For this reason we set out to verify the recovery rate of the skeleton (in other words the percentage of bones lost) during different archaeological excavations, through the study of 150 skeletons (75 adults and 75 subadults) from three north Italian necropoleis: the Roman site of “Milano Cattolica” (1st – 4th c. AD) a didactic excavation; “Lodi Vecchio, via Fregoni” a Longobard cemetery (7th c. AD) excavated by a private archaeological company and “Milano, via Monte Napoleone” (used between 1478 e 1547 AD), an emergency excavation. Results showed a maximum recovery rate of 82% (Milano Cattolica) and a minimal of 17% (Milano, via Monte Napoleone). Hands and feet were the areas most severely affected, loosing up to 60% of bones. Such loss was considered valid for the study only when the bone tissue of the skeleton was well preserved (with no or very little destructions or weathering) and the tomb had not been cut or disturbed. Even though it is obvious how important the presence of an osteologist is for the recovery of human remains, this research reveals how great, even with experienced archaeologists, the risk is of losing important material and how fundamental it is to verify the number and type of bones recovered for every single burial before concluding the excavation.