Abstract: The previously alleged “Ulunguhe Formation” in the Burqin region of Northern Xinjiang is lithologically different from the Ulunguhe Formation in its type-region, the Ulungur River area. The two regions are separated by a mountain of Paleozoic rocks. Therefore the sediments in two areas belong to different geological body respectively. The name “Ulunguhe Formation” should not be applied to the deposits in the Burqin region, for which, however, it is premature to name a new rock unit. A perissodactyl assemblage was collected from the sediments of Burqin. It consists of exclusively perissodactyls, including Cadurcodon cf. C. ardynensis, Gigantamynodon giganteus, Amynodontidae gen. et sp. indet., Indricotheriinae gen. et sp. indet., Rhinocerotidae gen. et sp. indet. , and Brontotheriidae gen. et sp. indet., and is comparable with the late Eocene mammal faunas of Asia ,such as Caijiachong fauna of Yunnan ,Ulangochu fauna and Urtyn Obo fauna from Nei Mongol of China, Guateg and Khoer-Dzan fauna from Mongolia ,and the Kusto fauna from Kazakhstan. The discovery of the late Eocene mammals in North Xinjiang indicates that the terrestrial biogeographic division into south and north provinces in the Asian continent had not been achieved by the late Eocene.

摘要： 1995 年以来作者等人在新疆准噶尔盆地北缘乌伦古河地区开展了第三纪哺乳动物地层研究工作。在调查研究该区乌伦古河组地层同时(叶捷等,2001a ,b) ,为搞清乌伦古河组的区域分布,我们在1999 年和2001 年先后两次前往布尔津地区考察了那里的“乌伦古河组”。在布尔津县城西北14km 处额尔齐斯河北岸的一片新生代露头,长期被视为乌伦古河组,因而时代也被定为始新世至渐新世,但一直没有确凿的化石依据。1999 年我们首次在该套地层中采集到哺乳动物化石(99027 地点) ,2001 年再次在同一地点、同一