中文摘要：

中新世是现代地理、生态、气候格局等形成的关键时期，是研究陆生哺乳动物演化与环境变化关系的理想时段。通过对内蒙古四子王旗大庙发现的中新世哺乳动物化石的研究，试图揭示同一区域哺乳动物群落演变过程、生态类型的变化及其与环境变化的关系。结果表明大庙共产出了3个时段的动物群，分别为早中新世谢家期、中中新世通古尔期以及晚中新世灞河期。从哺乳动物群落组成以及类群的演化序列上分析，大庙地区从早中新世谢家期至晚中新世灞河期生态环境相对稳定，明显不同于现代的干旱草原环境，应该是温湿的森林与开阔的草原共存的格局。

英文摘要：

Nei Mongol（Inner Mongolia）has been well-known in the paleontological society by rich vertebrate fossils, however, there are few well developed sections with superimposition of fossil levels. Here we present the preliminary results of our field seasons during 2006 - 2009 in the Damiao area, Central Nei Mongol. Three main fossil horizons represented by over 20 localities produce three faunas covering Early Miocene ,latest Middle Miocene and earliest Late Miocene respectively. The Early Miocene Xiejian fauna is represented by 21 species of 13 families in 5 orders. Large mammals include mainly small sized cervoids,e, g. Lagomeryx sp., Stephanocemas sp. nov, and Micromeryx sp. Small mammals are dominated by Metexallerix gaolanshanensis , Sinolagomys ulunguensis , Tachyoryctoides sp. nov, Prodistylomys wangae , Distylomys cf. D. tedfordi, Sinodonomys sp. ,Plesiosminthus sp. ,Heterosminthus sp. Pseudotheridomys sp. nov. ,and Eomyidae gen. et sp. nov. The late Middle Miocene fauna includes more than 30 species,sharing with the classical Tunggur fauna Mioechinus？ gobiensis , Desmanella storchi , Bellatona forsythmajori , Atlantoxerus orientalis , Heterosminthus orientalis , Protalactaga grabaui, Gobicricetodon flynni, and Stenofiber hesperus, however, with more diversified cervoids and a species of pliopithecid. The early Late Miocene fauna show great similarity with the previous fauna,except with the earliest record of Late Miocene elements Lophocricetus, Eozapus, Nannocricetus etc, and disappearance of the typical Middle Miocene Atlantoxerus,Democricetodon, and Heterosminthus. All three faunas have rich small mammals （insectivores, rodents and lagomorphs） and diversified cervoids. The similar relatively stable moderate humid and warm forest- faunal community structure and continuity of main lineages suggest a grassland environment from the Early Miocene to early Late Miocene The significant environment change seems to have happened after the earliest Late Miocene.