1980年在内蒙古二登图和哈尔鄂博古哺乳动物化石地点进行了化石筛洗,获得万余件小哺乳动物的颌骨和牙齿,这些材料包括了二登图动物群已知的2斗种和新增加的25种以上的食虫类、啮齿类和兔形类化石;其中一些属种,在中国或亚洲属首次发现。动物群中既含有许多地方性的种类,又有与欧洲和北美有亲缘关系的类型;其地质时代均为最晚中新世(土洛里晚期),也可能为早上新世(路西尼期)。 In 1980, fossil sieve washing was performed at the sites of Erdengtu, Inner Mongolia, and the ancient mammalian fossils of Hal, obtaining more than a thousand small mammals’ jaws and teeth. These materials included two known species And more than 25 new species of insects, rodents and rabbit-shaped fossils; some of them are found for the first time in China or Asia. The fauna contains many endemic species, as well as genus related to Europe and North America; the latest geologic age is Neoproterozoic (late ToloLori), and may also be Early Pliocene period).