The first record of Amphimachairodus horribilis from the Late Miocene of Mongolia

Mandibular fragments of a large-sized sabre-toothed cat from the Late Miocene (MN12/ MN13) of the locality Khyargas Nuur 2 (=Khirgis-Nur-2) in northwestern Mongolia are described.They are included in the hypodigm of the species Amphimachairodus horribilis, a common member of the Late Turolian (Late Baodean) fauna of Central Asia and China.The attribution to this species is based on the large size of the cheek teeth, the presence of slight serrations along their cristids, and the morphology of the metaconid-talonid complex on m1, with a slender, cutting, ventrally rounded, and well-differentiated metaconid, as seen in the lectotype of A. horribilis.Comparative analysis of the Mongolian remains and the morphologically close Amphimachairodus irtyshensis, from the nearby locality of Pavlodar (MN12) in Kazakhstan, suggested that the latter taxon is an independent, relatively mo re primitive species, rather than a synonym of more advanced A. horribilis.This is the fi rst report of A. horribilis from Mongolia and, so far, the northernmost occurrence of this species in Eurasia.This work also reconsiders the phylogeny of Eurasian representatives of Amphimachairodus.