Figure 3

Results on PCA based on the selected skull measurements. Plots primarily obtained by R Studio Software v.1.4.103 2020⁵⁰ packages ggplot2() v.3.3.3⁵¹ and prcomp() v.3.6.2⁵². (a, b) show the PC1 versus PC2-PC3 outcomes on the skull basal and lateral measurements, whereas (c, d) show the PC1 versus PC2-PC3 results for the skull basal measurements. The analyses have been developed by the Software R using the packages prcomp() and ggplot2(). The original database is given in Table S3, whereas the loadings plots are shown in Figure S3.