Analysis of the upper Miocene Hipparion samples of Hayranlı Haliminhanı in Sivas

The Hayranlı-Haliminhanı excavation site is located on the eastern side of the Hayranlı highway, on the hills of the Late Miocene aged along the Sivas-Ankara highway. It stands out as one of Turkey's richest vertebrate fossil beds, encompassing a habitat of shrubland and forest. The percentage of large mammal communities in Hayranlı indicates a Pikermian Chronofauna characterized by the dominance of Late Miocene open-terrain mammal species. Hipparion horses, known as a subgroup of the Equinae subfamily, are an extinct genus of horses that lived approximately 23 to 5 million years ago during the Miocene and Pliocene epochs. Hipparion horses, which became extinct in the New World about 5 million years ago, continued to survive in Eurasia and Africa until 11.4 to 1 million years ago. This thesis includes a systematic analysis of the Hipparion species at the Hayranlı/Haliminhanı fossil locality 19 aged MN11 (8.9-7.6 myö). The Hayranlı-Haliminhanı locality exhibits diversity not only in terms of other macro mammals but also among Hipparion horses. Although the locality resembles the typical Pikermian Savanna habitat and fauna, it is more closely related to Samos, Maragheh and Akkaş localities regarding Hipparion horses. Moreover, the enamel morphology of upper teeth, muzzle and metapod index analyses of Hipparion horses in the Hayranlı locality suggest that it likely hosted open rural biotopes along with probably seasonally transitioning dense woodland habitats. The Hayranlı locality reveals the coexistence of Hipparion species with different feeding types, preferring either open grasslands, semi-closed ecosystems (dense shrubland and woodland), or both habitats. As a result of this thesis, the following species were diagnosed at the Hayranlı/Haliminhanı 19 Locality: Cremohipparion aff. moldavicum, Cremohipparion cf. moldavicum Cremohipparion sp. (Large-sized form), Cremohipparion aff. proboscideum, Hipparion sp. (Hippotherium) (Large-sized form), Hipparion sp. (Medium-sized forms A, B, C), Cremohipparion sp. (Dwarf form).