Objective: Recent excavations of four mid-late 19th century Otago cemeteries aimed to elucidate the lived experiences of non-Māori setters of Otago, Aotearoa/New Zealand interred in unmarked or ‘lost’ graves. Histological analysis of archaeological teeth can reveal abnormally slowed enamel formation associated with physiological stress. Children are sensitive to stress events due to the demands of growth, and enamel provides a permanent kymographic record of developmental disturbances at the time of deposition. Here we explore these biomarkers of physiological stress during childhood in early settlers and their colony-born children.
Methods: Dental samples were prepared following established methods, and light microscopy was used to create composite digital images. Images were analysed using FIJI™ software to identify internal indicators of disruption to enamel secretion. Teeth develop in a predictable and well-established sequence, allowing the establishment of a chronology of non-specific developmental stress events during enamel formation.
Results: Internal indicators of physiological stress are identifiable in almost all sampled teeth (85/90). Prevalence and patterns of manifestation vary between individuals of different ethnic, socioeconomic, and climactic backgrounds. All groups demonstrate a peak in stress events occurring between two and five months of age.
Conclusions: Physiological stress may reflect push factors that stimulated emigration to ‘new’ world colonies such as New Zealand and demonstrate that hardships were not absent for early settlers. Infant vulnerability is apparent in the high prevalence of survived stress events in the first year of life.
Keywords: accentuated lines; dental histology; enamel formation disruption
Ethical statement: Extensive consultation with local communities and descendant groups was undertaken and appropriate disinterment licences and archaeological authorities were obtained prior to excavation.
Funding statement: Analyses were funded by a Marsden Fund Grant awarded to HB and PP (18- UOO-028), a Marsden Fast Start Grant awarded to AS (21-UOO-030), and a University of Otago Doctoral Scholarship.