Rancho La Brea stable isotope biogeochemistry and its implications for the palaeoecology of late Pleistocene, coastal southern California
Rancho La Brea stable isotope biogeochemistry and its implications for the palaeoecology of late Pleistocene, coastal southern California
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DOI：
10.1016/j.palaeo.2003.12.008
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发表时间：
2004-03-30
影响因子：
3
通讯作者：
Allen, J
中科院分区：
文献类型：
--
作者：
Coltrain, JB;Harris, JM;Allen, J
我们从兰乔拉布里亚(RLB)大型动物标本中采集了143个个体，测定骨胶原稳定碳(Delta(13)C)和氮(Delta(15)N)的同位素比率。这些收藏品是在美国加利福尼亚州洛杉矶盆地的沥青渗漏中发现的，年代从-40年到12ka。我们的发现表明，尽管胶原氮含量略有下降，但RLB骨骼残骸保存相对完好，大多数蛋白质可用于诊断饮食。食草动物三角洲(13)C和三角洲(15)N值随反省而变化，并与从花粉剖面重建的晚更新世植被的变化一致。尽管大气中的二氧化碳浓度很低，但我们在RLB没有发现依赖C-4草的证据。食肉动物Delta(15)N值表明，大狗、剑齿虎和黑豹争夺相似的猎物集合，对反刍动物和非反刍动物的捕食类型具有同等的依赖关系。美洲乳鼠的Delta(15)N值表明它们部分依赖于Delta(15)N值较低的植被(如固氮分类群)，这使它们有别于研究种群的其余部分。对晚更新世以来RLB值和欧洲动物群三角洲(15)N值的比较表明，南加州沿海经历了更大的干旱。(C)2004爱思唯尔B.V保留所有权利。
We sampled 143 individuals from Rancho La Brea (RLB) large faunal collections for bone collagen stable carbon (delta(13)C) and nitrogen (delta(15)N) isotope ratios. These collections were recovered from asphalt seeps in the Los Angeles Basin, California, USA, and date from -40 to 12 ka. Our findings indicate that despite a slight reduction in collagen nitrogen content, RLB skeletal remains are relatively well preserved and most yield proteins diagnostic of diet. Herbivore delta(13)C and delta(15)N values covary with rumination and are consistent with changes in late Pleistocene vegetation reconstructed from pollen profiles. We find no evidence for reliance on C-4 grasses at RLB, despite low atmospheric CO2 concentrations. Carnivore delta(15)N values indicate Canis dirus, Smilodon fatalis and Panthera leo atrox competed for similar prey sets and were equally reliant on ruminant and nonruminant prey types. The delta(15)N values of Mammut americanum indicate partial reliance on vegetation with lower delta(15)N values (such as nitrogen-fixing taxa), distinguishing them from the remainder of the study population. A comparison of RLB and European faunal delta(15)N values from the late Pleistocene suggests that coastal southern California experienced greater aridity. (C) 2004 Elsevier B.V All rights reserved.