Abstract:

The estimation of age-at-death for ancient human skeletal remains excavated from archaeological sites constitutes a fundamental and critical task for researchers in the field of human osteoarchaeology. This foundational work provides essential data for reconstructing demographic profiles, understanding paleoepidemiology, analyzing ancient lifestyles and health patterns, and interpreting funerary practices and social structures of past populations. Currently, the most frequently employed methodological approaches for age estimation in this context are the traditional observational method, which synthesizes morphological changes observed on the skeleton and dentition, and the transition analysis method, which is grounded in Bayesian statistics. Each method serves a distinct purpose in the analysis of human remains.The primary objective of both the traditional observational method and the transition analysis method is to estimate the biological age-at-death of an individual—that is, the physiological age reflected by the skeletal remains themselves. These methods rely on the well-established principle that the human skeleton and teeth undergo progressive, age-related changes in their morphology. In contrast, obtaining the chronological age—the actual calendar age since birth—of the deceased individual presents a significantly greater challenge in archaeological contexts. For historical periods in certain cultures, particularly in China, documentary sources, most notably epitaphs inscribed on burial tablets or stones, emerge as the primary and most reliable means of ascertaining the tomb owner’s precise chronological age at death. These inscriptions provide a direct historical record against which osteological age estimates can be compared and validated.

This paper presents a practical application and comparative evaluation of these two osteological methods. The research focuses on human skeletal remains excavated from two distinct cemetery sites in Shandong Province: the Fudamen Cemetery located in Liaocheng and the Dalan Village cemetery in Yantai. The core of the methodological approach involved independently applying both the traditional observational method and the transition analysis method to estimate the age-at-death for individuals from these assemblages. Subsequently, a crucial comparative analysis was undertaken by juxtaposing these osteological estimates against the chronological ages recorded in the epitaphs associated with the tombs, where available.The findings of this comparative study reveal significant and noteworthy patterns. The traditional observational method was found to systematically underestimate the age-at-death of the ancient residents interred at these sites. This underestimation bias was particularly pronounced and concerning for older adult individuals, whose ages were consistently assessed as younger than their documented chronological age. This phenomenon is widely recognized in osteology; age-related morphological changes in the skeleton become less distinctive and more variable after an individual reaches full maturity, making precise age estimation for older adults inherently challenging and often leading to systematic under-aging.

In contrast, the estimation results derived from the transition analysis method demonstrated a markedly closer alignment with the chronological ages provided by the epitaphs. The Bayesian statistical framework underlying transition analysis, which incorporates probability distributions of age-related changes derived from known-age reference populations, appears to provide a more robust and accurate estimation, especially for older individuals, by better accounting for the increased variability in skeletal aging.Therefore, this research successfully verifies the applicability and enhanced reliability of the transition analysis method for age estimation in an archaeological context, using historically documented epitaph ages as a robust verification benchmark. This empirical validation carries direct and profound implications for current practice. It strongly suggests that human osteoarchaeologists, when undertaking the crucial task of estimating age-at-death from ancient skeletal materials, must carefully consider the methodological framework they adopt. The choice between methods should not be arbitrary but should be a calculated decision based on several factors, with the preservation quality and completeness of the bone material itself being a primary consideration. In many cases, a combined approach, utilizing both the traditional observational method for a broad assessment and the transition analysis method for a more statistically refined estimate on key skeletal elements, might represent the most comprehensive strategy. Ultimately, this study underscores the importance of methodological rigor and cross-validation in human osteoarchaeology, contributing to the generation of more accurate and reliable paleodemographic data.

Key words: Epitaph-recorded age, age-at-death estimation, traditional observational method, transition analysis