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哺乳动物群的演替过程在重建古环境和古气候中具有重要的作用。群落线(cenogram)是将陆生哺乳动物群中非肉食性种类按体重分布顺序排列的一种曲线,并可在图中将肉食性种类单独排序,以便显示动物群的整体组成。通过与现生哺乳动物群的比较,化石动物群的群落线已经被用来推断古环境及其在地质历史时期的变化。基于甘肃临夏盆地晚新生代哺乳动物群的群落线进行古环境重建,时代从晚渐新世直到早更新世。大多数化石种类的体重通过下第一臼齿面积与体重的回归公式来估计,少数种类用其他牙齿或肢骨来估计。大多数体重估计的测量数据来自临夏盆地的化石,少数取自文献。对7个化石动物群分别计算群落线的统计结果,在此基础上进行古环境解释。这些分析揭示了临夏盆地在晚中新世、早上新世和早更新世具有开阔的环境,晚渐新世是半开阔的林地,而中中新世为比较紧密的森林;在晚渐新世和晚中新世早期气候干燥,晚中新世的其他时段以及早上新世和早更新世为半干旱环境,而中中新世时期相当湿润。
The succession process of mammalian herds plays an important role in reconstructing paleoenvironment and paleoclimate. The centimeter is a plot of the non-carnivorous species in terrestrial mammalian populations by body weight distribution, and the carnivorous species can be individually sorted in the diagram to show the overall composition of the fauna. By comparison with the existing mammalian fauna, the fossil fauna community line has been used to infer the paleoenvironment and its evolution during geological history. The paleoenvironmental reconstruction was based on the Late Cenozoic mammalian heritages of the Linxia basin in Gansu Province, dating from Late Oligocene to Early Pleistocene. The body weight of most fossil species is estimated by regression of the area of the first molar to the body weight, with a few species estimated using other teeth or limbs. Most body weight estimates come from fossils of Linxia Basin, with a few taken from the literature. Calculate the statistics of the community line for seven fossil fauna respectively, and explain the paleoenvironment on this basis. These analyzes revealed that the Linxia Basin had an open environment in the late Miocene, the Oligocene and the Early Pleistocene, the Late Oligocene being a semi-open forestland and the Middle Miocene being a relatively dense forest, while in the Late Oligocene, And the early late Miocene climate was dry, the late Miocene and other periods as well as the early Pliocene and Early Pleistocene semi-arid environment, while the Mid-Miocene was quite humid.