Abstract: Newly discovered fossil taxa and preliminary revision of the old collection from the Bahe and Lantian formations allow a re-interpretation of the mammalian faunal sequence of the Chinese Late Miocene. The distribution of fossil taxa in the strata shows a major turnover event within the late Miocene, at a time slightly preceding the sedimentological change represented by the boundary between the Bahe and Lantian Formations (ca. 7Ma). The mammal fauna postdating the change shows a strong resemblance to the classic Baodean mammal faunas of North China. Based on this turnover event a resurrection of the Bahean Land Mammal Age, predating the Baodean LMA within the late Miocene, would be possible. The Bahean/Baodean turnover event was ecological as well as taxonomic and suggests significant climatic change at this time, possibly driven by onset or intensification of the East Asian summer monsoon circulation system.

摘要： 自20 世纪60 年代,陕西蓝田地区就以连续的晚新生代地层及丰富的哺乳动物化石而成为研究中国晚新生代哺乳动物与地层划分对比的经典地区之一。李传夔等(1984) 根据灞河组发现的哺乳动物化石建立了灞河期,并与欧洲的Vallesian 期对比。邱占祥等(1990 ,1995) 认为化石证据不充分,而将其与保德期合并。近年来,黄土高原三趾马红粘土大量的年代学资料表明,红粘土沉积最早可能开始于约8Ma 前。因此,狭义的保德期可能只代表了晚中新世晚期,晚中新世哺乳动物分期的再划分问题又重新被提出。 自199