Ontogenetic Allometry of the Human Scapula: A Geometric Morphometrics Study in Two Portuguese Reference Skeletal Samples

Background/Objectives: The identification of individuals from human remains is crucial in any scenario where their identity is unknown. The study of ontogenetic allometry, which refers to proportional changes in the shape and size of bones during growth, provides important baseline information for constructing biological profiles. Methods: This study focuses on the analysis of the ontogenetic allometry of the scapula in Portuguese reference skeletal samples, using geometric morphometric techniques. The sample includes 140 individuals (67 females, 73 males), ranging from birth to 89 years old. Scapulae were photographed, and seven landmarks and forty semi-landmarks were digitized using the “tps” programs. Statistical analyses were performed using the MorphoJ (v. 1.08.02) and PAST (v. 5.2) programs. Results: The results point to a significant and continuous growth of the scapula in the early stages of life, with a tendency to stabilize after adolescence. Centroid size significantly influenced shape variation across the full sample. Conclusions: These findings provide a descriptive baseline of scapular development that can aid future anthropological and forensic research, including studies on population variation and age-related morphological trajectories.