Goedert Jean, Amiot Romain, Berthet Didier, Fourel François, Simon Laurent, Lécuyer Christophe
CNRS, UMR 5276 LGL-TPE, Univ Lyon, Université Lyon 1, Ens de Lyon, 69622, Villeurbanne, France.
Musée des Confluence de Lyon, Lyon, France.
Naturwissenschaften. 2020 Feb 4;107(2):10. doi: 10.1007/s00114-019-1664-3.
Reconstructing the living environment of extinct vertebrates is often challenging due to the lack of proxies. We propose a new proxy to the living environment based on the combined oxygen and sulphur stable isotope analysis of vertebrate hydroxyapatite. We tested this isotopic proxy to 64 biogenic apatite (bones) samples that represent a wide spectrum of the extant vertebrate phylogenetic diversity including crocodiles, snakes, turtles, mammals, birds, lizards, fish and amphibians. We show that the combination of these two isotopic systems allows the living environment of all these vertebrates to be unambiguously distinguished between freshwater (aquatic vs semi-aquatic), seawater (aquatic vs semi-aquatic) and terrestrial. The main goal of this study is to provide a present-day isotopic reference frame and to discuss methodological issues that will serve to interpret future oxygen and sulphur isotope results obtained either from fossil or modern skeletal material. This new isotopic approach of combined oxygen and sulphur isotope analysis will be particularly useful to document major aquatic-terrestrial transitions in the fossil record but also to better constrain the living environment of some present-day species.
由于缺乏代理指标，重建已灭绝脊椎动物的生存环境往往具有挑战性。我们基于脊椎动物羟基磷灰石的氧和硫稳定同位素联合分析，提出了一种新的生存环境代理指标。我们对64个生物成因磷灰石（骨骼）样本测试了这种同位素代理指标，这些样本代表了现存脊椎动物系统发育多样性的广泛范围，包括鳄鱼、蛇、龟、哺乳动物、鸟类、蜥蜴、鱼类和两栖动物。我们表明，这两种同位素系统的结合能够明确区分所有这些脊椎动物在淡水（水生与半水生）、海水（水生与半水生）和陆地的生存环境。本研究的主要目标是提供一个现代同位素参考框架，并讨论有助于解释未来从化石或现代骨骼材料获得的氧和硫同位素结果的方法学问题。这种氧和硫同位素联合分析的新同位素方法对于记录化石记录中的主要水陆过渡，以及更好地限制一些现代物种的生存环境将特别有用。
