Three-dimensional morphological variation and sexual dimorphism in the humerus of dromedary camels (Camelus dromedarius) from El Oued region: a geometric morphometric analysis

This study investigates the three-dimensional morphological variation and allometric relationships in the humerus of dromedary camels (Camelus dromedarius) from the El Oued region, with a focus on sex-based differences. The aim is to analyze the morphological diversity and sexual dimorphism in the humeri of dromedary camels using advanced geometric morphometric techniques. This includes discerning patterns of variation and covariation, particularly related to sexual dimorphism and size-related shape changes. A sample of 59 humeri (29 males and 30 females) was collected. High-resolution three-dimensional scans were used to capture detailed shapes, followed by Procrustes superimposition and Principal Component Analysis to analyze the data. The analysis revealed significant sexual dimorphism, with male camels having more robust and thicker humeri compared to the more slender and delicate humeri of female camels. The allometric analysis showed notable size-related shape changes, especially in the deltoid tuberosity and distal epiphysis regions. The study underscores the presence of sexual dimorphism and its impact on the functional morphology of camelid skeletal structures. The findings provide valuable comprehension into the adaptation pressures and functional demands shaping these bones, demonstrating the utility of geometric morphometrics as a powerful tool in skeletal morphology studies. This research sets a new standard for future studies by integrating high-resolution three-dimensional scanning with sophisticated morphometric analyses.