Fig. 1: Ruminant astragalus shape variation assessment.

A Principal component analysis (PCA) based on Procrustes coordinates including all extant and extinct ruminants. The virtual deformations along PC1 and PC2 are represented by the warped model corresponding to the mean individual deformed to reach the shape of the maximal individual on the axis. The heat maps show the regions with the most warping along positive (red) and negative (blue) scores of each PC, and light green indicates no deviation. Abbreviations: Ant. (Anterior); Post. (Posterior); Lat. (Lateral); Med. (Medial). B Venn diagram illustrating the variation partitioning analysis (VARPART) used on astragalus shape among extant ruminants. Values represent the adjusted R² for the size (log-transformed centroid size), the clade (assigned), the habitat (assigned categories), and the interaction of the corresponding explanatory variables.