1976年 第14卷 第4期: 228~233
编辑：周明镇 齐陶 李荣
摘要：Recently an assemblage of mammalian fossils were collected from the Nomogen Formation cropped out at two localities (Haliut and Gonghydong) in the Nomogen Commune, Si-Zi-WangQi, Nei Mongol(= Inner Mongolia). The mammalian fauna consists of 15 known species (see list on page 233)，among which six are known previous1y from the Upper Paleocene Gashato Formation of the Mongolian People`s Republic. This indicates that the Nomogen Formation are an equivalent or close correlative of the Gashato. Based on the field stratigraphical evidences it seems without much doubt that the Paleocene mammal-bearing beds is really a westward extension of the "Arshanto Formation ", which was long thought to be of middle Eocene age. This and related problems have been more fully dealt with elsewhere (Zhou, Zhai and Qi, in Press). The fossil-bearing bed differs from that of the Gashato in being one more typical of lacustrine origin. About 90% of the fossils in a total of some 150 registered specimens belong to two forms, i. e. Paleostylops iturus and a moderate-sized species of taeniolaboid multituberculate. While the former is especially abundant; the latter species is represented by many isolated teeth and a number of skulls preserved in hard calcareous concretions.