Variations in the anatomical structure of the pterion among populations from various global regions

Anatomical variations in the structure of the pterion were examined in various craniological series represent-ing modern populations from Australia, Melanesia, Southeast Asia, North Asia, America, and Europe, encom-passing 2035 adult crania. The comparison of populations based on the frequency of nonmetric traits revealed significant diversity across regions. Notably, the sphenoparietal connection is most frequent in European and South Asian populations, as well as among Native Americans, while it is least common among African groups. The frontotemporal connection predominates among Australian Aborigines and Melanesians and is also common in African populations but is almost non-existent in Europeans. The X-shaped pterion is most frequently observed in the Eskimos of Chukotka and the Chukchi, as well as among Somali and Tanzanian populations. A high fre-quency of epipteric bones is particularly characteristic of Southern Indians, Burmese, Australians, and Melane-sians. Pairwise comparisons of populations were conducted using Smith's Mean Measure of Divergence (MMD). To visualize the data from individual regions, the method of Multidimensional Scaling (MDS) was applied to the matrices of biological distances. The MDS plot for the North Asian region revealed distinct clusters of the Arctic, Baikal, Cen-tral Asian, and Ural groups, aligning with G.F. Debetz's classification based on morphological similarities among populations. In the MDS plot for the South and Southeast Asian, American, and African populations, Australians and Melanesians formed a separate cluster; Pueblo Indians were closely aligned with Peruvians, South Indians with Burmese, Malays merged with Papuans, and African populations were positioned relatively close to each other. In Europe, Caucasian groups formed a distinct cluster. On the combined graph, the populations were clearly divided by regions. The results obtained indicate that the spatial arrangement of populations on the graphs approximately mir-rors their genetic connections and shared origins. This suggests that nonmetric variations in the pterion area are more likely determined by genetic rather than ecological factors and can be considered taxonomically valuable traits at the regional level. Investigating the structure of the pterion in an evolutionary context may shed light on broader questions concerning the evolution of the skull and the mechanisms influencing its formation.