A controversial taxon, Hipparion plocodus, is reviewed in the present study. Hi. plocodus has been confirmed to be a valid species with definite diagnostic characteristics, represented by cranial specimens from Baode, Shanxi Province. The phylogenetic analysis performed in the present study, with a new matrix, shows that Hi. plocodus forms a monophyletic group with a European species, Hippotherium malpassii. Actually, no close relationship between so-called Hm. malpassii and the genus Hippotherium has been identified, and the record of stratigraphic range of this genus in late stage of Late Miocene is currently absent. Herein previously Hi. plocodus and Hm. malpassii have both attributed into “Hipparion” before the discovery of better material. Evolutionary stages and correlative absolute age showed that these two species should derive independently from some primitive clade. During the late stage of the Late Miocene, the development of the Asian summer monsoon enhanced the humidity of China, with forest and wood habitats expanding considerably under this setting. As the result, one Eurasian closed-habitat lineage thus extended its range into China, which had become very suited for it, give rise to “Hi.” plocodus.

对一个具有争议的类群Hipparion plocodus进行了回顾。山西保德的头骨材料具有明确的鉴定特征，证实Hi. plocodus为一有效种。使用新的特征矩阵进行系统发育分析，表明Hi. plocodus和欧洲种Hippotherium malpassii构成一个单系群。事实上所谓的Hm. malpassii和Hippotherium属无较近的亲缘关系，而该属目前无晚中新世晚期分布记录。因此之前所定义的Hi. plocodus和Hm. malpassii在更好的材料发现之前暂时归入“Hipparion”属当中。二者演化水平略有差异，时代相当，表明它们独立起源于某一更原始类群。在晚中新世晚期，亚洲夏季风的盛行加强了中国地区的湿润程度，森林和灌木林生境在这一背景下迅速扩张。最终令欧亚大陆某一喜好封闭环境的类群向中国扩散，在这片适应的土地上演化出了“Hi.” plocodus。