Teeth Enamel Ultrastructural Analysis of Selected Equidae Taxa

This paper presents historical and evolutionary insights into the “tarpan” group of small horses by examining molar tooth enamel ultrastructure. Mathematical methodologies were applied to enhance the analysis. Tooth enamel from species such as Equus gmelini (tarpan), E. latipes, and E. hydruntinus from Pleistocene Ukrainian localities, E. przewalskii from the Chornobyl Exclusion Zone in Ukraine, and E. caballus form sylvaticus (Polish konik) from Roztocze National Park, Poland, underwent scanning microscope examination. Measurements of enamel structures, including prisms (PE) and interprismatic matrix (IPM), were conducted, with the K-index used as their ratio, categorized by enamel type (I, II, III). The findings confirmed that the crystal structures of enamel in these horse groups vary based on genus evolution, diet, and environmental conditions, shaping the enamel’s morphological features. Through analysis, clusters were identified, allowing for potential reconstructions of relationships among study groups. The results revealed distinct differences between species, enabling their classification within an established phenogram. Two primary clusters emerged: one consisting of extinct small horse forms from diverse localities and another grouping modern forms. Notably, the Late Pleistocene European species E. latipes showed close affinities to the latter cluster.