Non-metric traits of dental crown morphologies in the gallo-roman collection from La Favorite’s necropolis (Lyon, France) using the Arizona State University dental Anthropology system

• Examined dental morphology in a Roman necropolis of Lugdunum. • Contributes to understanding non-metric dental traits in well-preserved Gallo-Roman remains, which is rare due to predominant cremation practices of the era. • Dental trait analysis suggests the potential presence of individuals with diverse geographical origins in the Gallo-Roman population. To describe the non-metric dental traits (NMTs) of the Gallo-Roman collection from La Favorite and explore their implications for understanding biological diversity and migration patterns within the population. A total of 1,464 permanent maxillary and mandibular teeth from the craniofacial skeletons of 86 individuals from La Favorite’s necropolis were analyzed. Twenty-eight NMTs were selected to characterize the crowns of permanent teeth using the Arizona State University Dental Anthropology System (ASUDAS). Inter- and intra-operator reproducibility was tested on twenty maxillae and twenty mandibles. Additionally, rASUDAS software was used to estimate the geographical origins of three individuals based on their dental trait profiles. Inter-operator kappa values ranged from 0.834 to 0.974, and intra-operator kappa values ranged from 0.798 to 1.0. The frequency of non-metric dental traits was analyzed using ASUDAS for presence, scores, and distribution. rASUDAS software was used to estimate the geographical origins of individuals based on dental trait frequencies. The rASUDAS analysis suggests that two individuals from the La Favorite collection may have origins in regions outside of the local Gallo-Roman population, with probabilities indicating Southeast Asia & Polynesia, Western Eurasia, and Sub-Saharan Africa as potential geographical origins. The frequency of most NMTs aligns with data from European collections dating from the first centuries CE. The observed variability in dental traits, along with osteo-dental and historical data, suggests a heterogeneous population in Lugdunum, supporting the presence of foreign individuals from regions such as Asia, Africa, and the broader Mediterranean world. The use of rASUDAS for a subset of individuals highlights the potential for dental anthropology to provide insights into ancient population mobility and diversity. The analysis of non-metric dental traits in the rare and well-preserved La Favorite collection provides valuable insights into the biological diversity and cultural interactions in Lugdunum during the first three centuries CE. The findings support the presence of foreign individuals in this Gallo-Roman population and contribute to our understanding of ancient migration patterns.