Discovery of two crania of Equus (Sussemionus) ovodovi Eisenmann & Vasiliev, 2011 (Mammalia, Perissodactyla) from the Late Pleistocene of Khakassia, Russia

Abstract

Two crania, 40 000 years old, collected inside the Fanatics Cave in Khakassia (Southern Siberia) have improved our knowledge of Equus ovodovi Eisenmann & Vasiliev, 2011 anatomy. Equus ovodovi belongs to the subgenus Sussemionus Eisenmann, 2010 all other members of which went extinct during the Middle Pleistocene. By cranial morphology as well as by other anatomical and molecular characters, E. ovodovi differs from all other Equus species and in particular from E. hydruntinus Regàlia, 1907 to which it was initially referred. E. ovodovi has narrower choanae and supra-occipital crest and a longer muzzle. By these features it resembles E. vekuae Eisenmann, 2022 from the Early Pleistocene of Dmanisi, Georgia, another species belonging or closely related to the subgenus Sussemionus. It differs from it, however, by the position of hormion relative to basion and staphylion.