Museum of Paleontology, University of Michigan, 1109 Geddes Avenue, Ann Arbor, MI 48109, USA.
Proc Biol Sci. 2013 Jan 7;280(1750):20122138. doi: 10.1098/rspb.2012.2138. Epub 2012 Nov 7.
The exceptional fossil sites of Cerro de los Batallones (Madrid Basin, Spain) contain abundant remains of Late Miocene mammals. From these fossil assemblages, we have inferred diet, resource partitioning and habitat of three sympatric carnivorous mammals based on stable isotopes. The carnivorans include three apex predators: two sabre-toothed cats (Felidae) and a bear dog (Amphicyonidae). Herbivore and carnivore carbon isotope (δ(13)C) values from tooth enamel imply the presence of a woodland ecosystem dominated by C(3) plants. δ(13)C values and mixing-model analyses suggest that the two sabre-toothed cats, one the size of a leopard and the other the size of a tiger, consumed herbivores with similar δ(13)C values from a more wooded portion of the ecosystem. The two sabre-toothed cats probably hunted prey of different body sizes, and the smaller species could have used tree cover to avoid encounters with the larger felid. For the bear dog, δ(13)C values are higher and differ significantly from those of the sabre-toothed cats, suggesting a diet that includes prey from more open woodland. Coexistence of the sabre-toothed cats and the bear dog was likely facilitated by prey capture in different portions of the habitat. This study demonstrates the utility of stable isotope analysis for investigating the behaviour and ecology of members of past carnivoran guilds.
西班牙马德里盆地的塞罗德洛斯巴托伦（Cerro de los Batallones）是一处特殊的化石遗址，保存有大量晚中新世哺乳动物的遗骸。我们从这些化石组合中推断出了三种同时代肉食性哺乳动物的饮食、资源分割和栖息地，这是基于稳定同位素得出的结论。这些食肉动物包括三种顶级掠食者：两种剑齿猫科动物（猫科）和一种熊犬（熊科）。牙齿珐琅质中的食草动物和食肉动物的碳同位素（δ(13)C）值表明，存在一个以 C(3)植物为主的林地生态系统。δ(13)C 值和混合模型分析表明，两种剑齿猫科动物，一种体型与豹子相当，另一种体型与老虎相当，它们食用的食草动物的 δ(13)C 值来自生态系统中树木更繁茂的部分。这两种剑齿猫科动物可能会捕食不同体型的猎物，而较小的物种可能会利用树冠来避免与较大的猫科动物相遇。对于熊犬来说，δ(13)C 值较高，与剑齿猫科动物的差异显著，表明其饮食包括来自更开阔林地的猎物。剑齿猫科动物和熊犬的共存可能是由于它们在栖息地的不同部分捕捉猎物而得以实现的。本研究证明了稳定同位素分析在研究过去肉食动物群体行为和生态学方面的有效性。
