Interpreting Developmental Stress in Archaeological Pigs: the Chronology of Linear Enamel Hypoplasia

Abstract

By recording abnormal incremental lines, known as linear enamel hypoplasia (LEH), visible on the tooth crowns of numerous archaeological pigs' teeth, it has been possible to construct a chronology of physiological stress for five different archaeological assemblages. The results confirm that LEH is a common occurrence in all the populations investigated. Given the geographical and temporal differences between the sites studied, LEH in pigs is thus likely to be a frequently observable phenomenon. Analysis of the frequency distribution of the height of each LEH lesion on the lingual surface of each cusp of each molar shows that the occurrences of LEH follow clear patterns. Taking into account the published data on tooth crown growth in the modern domestic pig, it is proposed that birth and weaning are the direct causal agents of the two discrete peaks noted on the first permanent molar (M1), whilst a period of under-nutrition encountered during the first winter of the animals' life is thought to be the main causal factor for the occurrence of the single distinct LEH peak noted on the second permanent molar (M2). A broad peak on the third permanent molar (M3) is similarly interpreted. These links between patterns of LEH and the normal developmental physiology of the animal open a number of possibilities for interpretation.