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古脊椎动物学报 ›› 2006, Vol. 44 ›› Issue (02): 109-132.

• 古脊椎动物学报 •    下一篇

中国北方“第四纪(或亚代)”环境变化与大哺乳动物演化

邱占祥   

  • 出版日期:2006-06-15 发布日期:2006-06-15

Quaternary environmental changes and evolution of large mammals in North China

Qiu Zhanxiang   

  • Published:2006-06-15 Online:2006-06-15

摘要: 地质年表2004的筹备和发表使关于“第四纪”概念、时限、阶元的讨论达到了高潮。目前的情势是,其下限下移至~2.6 Ma几乎已成定局;其阶元究竟是“纪”还是“亚代”正在表决中(初步表决倾向于后者)。这样一来,“第四纪”就包括以海相地层为基础建立的晚上新世、更新世及全新世三大部分。中国北方“第四纪”大哺乳动物的研究已有很长的历史。现在应该根据新的情势重新审视其演化的阶段性及其与~2.6 Ma以来环境变化之间的关系。对环境变化和大哺乳动物化石已有资料的分析表明:1)~2.6 Ma是北极冰盖大规模扩大,季风气候急

Abstract: Preparation and publication of GTS 2004 led the discussion on the concept, time duration and rank of the " Quaternary" to a new height. Pending the final ratification, it seems almost certain that its lower boundary is to be lowered to —2. 6 Ma, but its rank as Period or Sub-Era remains to be decided. At any rate, the " Quaternary" will encompass 3 major units: the late Pliocene, Pleistocene and Holocene, which are chiefly based on marine deposits. The " Quaternary" large mammals of North China has been extensively studied for a long time. Now it is advisable to review their evolution in light of the new perspective. Tentative analysis of the available paleoenvironmental data in conjunction with the evolutionary phases of the mammalian faunas shows the following: 1) —2. 6 Ma is certainly a critical period, at least in North Asia, when a number of events concurred. These include the great expansion of the Arctic ice sheet, the beginning of large-scaled loess deposition induced by intensification of monsoon system, and the extinction of large numbers of typical Hipparion fauna by —2. 6 Ma. 2) 2. 6 l. 3 Ma is a period flourished with archaic types of " Quintenary" large mammals. As immigrants from North America, Equus and Megantereon entered Eurasia at the beginning of the period. Large numbers of typical “Quaternary” genera appeared, like Eirictis, Metes, Crocuta, Coelodonta, Eucladoceros, Elaphurus, Leptobos, etc. Climate of this period, especially its later half, was comparatively stable, rather mild in general, as shown in Ding et al. 's Chiloparts. 3) l. 3 —0. 13 Ma is characterized by particular development of Sinomegaceros. Typical Middle Pleistocene species as typified by ZKD fauna appeared, like Canis variabilis, Pachycrocuta sinensis, Megantereon inexpectatus, Dicerorhinus kirchbergensis, etc. A peculiar aspect is the invasion of Oriental elements into the south part of the North China, like Ailuropoda, Stegodon orientalis, Megatapirus, Elaphodus, Capricornis, etc., at the very beginning of this period. Climate of this period was highly variable, with at least 3 cold and one prolonged warm episodes (LIS, L9, L2 and S5 in Chiloparts). Therefore, this period might be further subdivided when in-depth study is carried out in the future. 4) 0. 13 — 0. 011 Ma is characterized by a mixture of survived coldadapted forms with living species. Climate of this period was probably mild. Such a climatic condition might have caused the adaptive radiation of the survived cold-adapted forms, as exemplified by the bizarre-antlered giant deer. 5) 0. 011 Ma Recent is equivalent to Holocene. Its mammalian fauna became modernized, with the final extinction of holdovers of the glacial period exemplified by mammoth and woolly rhinoceros. We suggest that the above 4 phases be designated from earliest to latest as NCMQ1~ 4. The NCMQ1 —2 boundary does not coincide with that of Plio-Pleistocene (1. 8 Ma), neither with that of Early-Middle Pleistocene (0. 78 Ma). However, such a subdivision is rather close to the subdividions based on mammals currently adopted in North America and Europe. The Blancan-lrvingtonian boundary (in N ALMA) lies at — 1. 35 Ma. The upper boundary of the European Villafranchian lies also between l. 4~ 1. 1 Ma.