甘肃省临夏盆地渐新世—中中新世爪兽科和马科(奇蹄目,哺乳纲)化石

Oligocene to Mid-Miocene Chalicotheriidae and Equidae(Perissodactyla,Mammalia) fossils from the Linxia Basin, Gansu Province

甘肃临夏盆地因巨厚的新生代陆相沉积和大量的哺乳动物化石而闻名于世,其中奇蹄目化石因在生物地层和古环境研究方面有重要意义而备受关注。本文描述了甘肃省临夏盆地发现的3种爪兽和一种安琪马化石。椒子沟地点的Schizotherium ordosium进一步证实椒子沟组的时代当属晚渐新世;老沟地点和上沟地点的Schizotheriinae gen. et sp. indet.和Anisodon sp.表明在中中新世全球气候适宜期,我国北方爪兽类的生物多样性是比较高的;上沟地点的Anchitherium gobiense是通古尔期的代表物种之一,它的存在说明上沟化石地点的时代为中中新世晚期。爪兽类和安琪马都是林栖型的动物,指示了临夏盆地晚渐新世以疏林环境为主,中中新世晚期温湿森林更加普遍。

Three species of chalicothere and one species of anchitheriine horse from the Linxia Basin, Gansu Province are described. Schizotherium ordosium from Jiaozogou confirmed the geological age of this locality is Late Oligocene. The Mid-Miocene Schizotheriinae gen. et sp.indet. and Anisodon sp. from Laogou and Shanggou localities show a high diversity of chalicotheres in North China during the Mid-Miocene Climate Optimum. Anchitherium gobiense, a representative species of Tunggurian Stage, from Shanggou locality indicates a geological age of late Middle Miocene. The appearance of chalicothere and anchitheriine horse,both forest-adapted animals, points out a sparse forest dominated environment during the Late Oligocene and a warm and wet forest environment during the late Middle Miocene in the Linxia Basin.