Estimating age-at-death is a central aspect of bioanthropology, as it allows researchers to reconstruct part of an individual’s biological identity or to analyze mortuary recruitment within a necropolis in an archaeological context. Among the various age categories, immature individuals occupy a particularly significant place in bioanthropological studies. Their skeletons, still undergoing growth, display a series of developmental markers that enable a relatively precise estimation of age-at-death. In adults, determining age-at-death is often challenging, because most bones have reached full maturity and undergo remodeling that varies between individuals. By contrast, young adults represent a particularly interesting category for bioanthropology, as their skeletons still exhibit signs of bone maturation. This master’s research project aims to improve the identification of young adults and refine age-at-death estimates by focusing on three late-maturing skeletal markers. To achieve this, we are working with individuals from the Simon Reference Collection of identified skeletons, for whom the age-at-death is known.