Carbon isotopic evidence for the emergence of C4 plants in the Neogene from Pakistan and Kenya
Carbon isotopic evidence for the emergence of C4 plants in the Neogene from Pakistan and Kenya
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DOI：
10.1038/367162a0
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发表时间：
1994
期刊：
影响因子：
64.8
通讯作者：
M. E. Morgan;J. Kingston;B. Marino
中科院分区：
文献类型：
--
作者：
M. E. Morgan;J. Kingston;B. Marino
详细的陆地环境古记录是解释晚中新世哺乳动物进化的关键。在这里，我们评估现代热带草原（C4）生物群落，现代动物群的重要生态系统的发展。我们给出了两个层序动物群的釉磷灰石13 C/12 C同位素比值，这两个层序是巴基斯坦北方Potwar高原的Siwaliks和肯尼亚的Tugen Hills层序（图1）。我们的数据不支持以前的建议，一个有限的全球日期C4出现与大气CO2减少约700万年前1。相反，C4草在940万年前首次被记录为巴基斯坦的膳食成分，并在接下来的几百万年中作为觅食资源增加。在肯尼亚，C4草存在于1530万年前，但直到700万年前才成为食草动物的主要食物资源。广泛的C3和C4饮食信号的特点最新中新世/上新世的肯尼亚。
DETAILED palaeorecords of terrestrial environments are critical for interpretations of the late Miocene mammalian evolution. Here we assess the development of modern tropical grassland (C4) biomes, an important ecosystem for modern faunas. We present enamel apatite13C/12C isotope ratios of fauna from two sequences, the Siwaliks from the Potwar Plateau in northern Pakistan, and the Tugen Hills Succession in Kenya (Fig. 1). Our data do not support previous suggestions of a restricted global date for C4 emergence associated with decreased atmospheric CO2around 7 Myr ago1. Instead, C4 grasses are first recorded as a dietary component in Pakistan at 9.4 Myr and increase as a foraging resource over the next few million years. In Kenya, C4 grasses are present by 15.3 Myr but are not the primary dietary resource of herbivores until 7 Myr. A wide range of C3 and C4 dietary signals characterizes the latest Miocene/Pliocene of Kenya.