Contributions of phenetic relationship and stable isotope analysis (δ13C, δ15N, δ18O) to the study of a mortality crisis in the catacomb of Saints Peter and Marcellinus in Rome (1st-3rd century AD)

The catacomb of Saints Peter and Marcellinus located in the south-east of Rome approximately contains 25 000 graves dated from the 3rd to the 5th century AD. Seven newly discovered rooms having an unusual organization in the heart of the catacomb were investigated in 2003. Excavations of these rooms revealed a mass grave, where 3000 corpses were laid together. These individuals were stacked in rows apparently following a common fatal incident. Presumably, this epidemic crisis occurred between the 1st and the 3rd century AD. The specific funerary treatment (textile wrapping and plaster) recalls mummification and might be related to exogenous practices, possibly connected to Early Christians. Moreover, the presence of rare and expensive materials (e.g., Baltic amber, resins and gold threads) may indicate a high social status. Stable isotope analyses (carbon, nitrogen and oxygen) of bone collagen, bone apatite and tooth hydroxyapatite were carried out on 111 individuals to obtain further information on their diet and residential mobility. Additionally, a study of dental nonmetric traits was conducted on 200 individuals to define the biological distance between the deceased and to assess their phenetic similarity. The combination of these two approaches will bring new insight into the homogeneity of the Early population of the catacomb of Saints Peter and Marcellinus and the relationship between funerary practices and geographical origin of buried individuals