作者:马 姣,王 元,金昌柱,张瀚文,胡耀武
摘要:为了进一步地探索亚洲象的摄食行为,运用稳定同位素的序列取样(serial/sequential sampling)新方法,首次对晚更新世笆仙洞遗址的三个亚洲象臼齿牙釉质(1个DP4, 2个M1)进行研究。结果表明,三个亚洲象个体的δ13C和δ18O内部差异均很小,未见季节性变化,虽然可能存在断奶及迁徙导致的数据波动,但总体来看依然表现出在牙釉质形成的长期过程中较为稳定的摄食行为。之前笆仙洞亚洲象动物群的整体取样(bulk sampling)同位素研究结果中,亚洲象的数据分布较为分散。而本次研究中较小的个体内部差异,则反向证实了宽泛分布的数据确实代表了灵活的摄食行为,并非取样位置的不同所致。这也进一步证明在气候温暖的东南亚地区,长鼻类动物的牙釉质整体取样工作可以提供可靠的古摄食行为及古生态信息。
关键词:中国南部,晚更新世,亚洲象,稳定同位素,序列取样牙釉质,摄食行为
卷期:第57卷,第3期
A preliminary study of serial stable isotope analysis tracks foraging ecology of fossil Asian elephants in South China
MA Jiao, WANG Yuan, JIN Chang-Zhu, ZHANG Han-Wen, HU Yao-Wu
Abstract Until now, feeding ecology has been found to play a significant role in the evolution of Asian elephant Elephas maximus. As the most widely-applied method in this field, bulk stable isotope analysis on tooth enamel had revealed important evidence on their paleodiet and paleoecology. However, it might be not skilled at reflecting the overview of the paleoecology of elephants, considering their huge tooth mophology and long dental ontogeny process. A newly-developing serial sampling strategy on tooth enamel sections could provide an effective approach reconstructing the long-term individual life history of mammals covering the whole tooth formation time with higher precision. In this study, serial sampling isotope analysis was firstly undertaken on tooth enamel of Asian elephants from Baxian Cave, South China during the Late Pleistocene. The within-tooth isotopic variations of three teeth (one DP4 and two M1s) are all surprisingly subtle (standard deviations of δ13C and δ18O values are all less than 0.6‰), though some obvious variations might be caused by weaning and/or possible migration. No seasonal variation was observed, possibly indicating that these elephants had a stable foraging ecology. Back to our previous bulk tooth enamel isotope analysis on this same site, we could confirm that the varied bulk isotope results of Asian elephants factually represent their flexible foraging ecology. We may thereby conclude that the increasing bulk isotopic analysis in this region can provide a reliable paleoecological proxy for Pleistocene proboscidea in the warm regions of South and Southeast Asia.
Key words South China, Late Pleistocene, Elephas maximus, stable isotopes, serial sampling, tooth enamel, foraging ecology