Data from: Carnivoran resource and habitat use in the context of a Late Miocene faunal turnover episode

We investigate resource and habitat use by apex predators through stable isotope analysis at two Spanish Late Miocene localities: Los Valles de Fuentidueña (~9.6 Ma, LVF) and Cerro de los Batallones (~9.1 Ma, BAT). The temporal window represented by LVF and BAT was crucial in the shaping of the current Iberian mammalian structure because it corresponds to the initial stages of a faunal turnover episode and regional environmental change at ~9.5–8.5 Ma (Vallesian–Turolian transition), associated with an increase in the seasonality of precipitation. Herbivore and carnivore δ13C and δ18O values do not point to significant changes in either the vegetation cover (a woodland to mesic C3 grassland) or the hydrological regime during the time lapse represented between LVF and BAT. This suggests that the environmental shift recorded around the Vallesian–Turolian boundary may have occurred later in time, since LVF and BAT ages are synchronic with the onset of the turnover event. From the standpoint of predator–prey evaluation by means of stable isotope analysis, statistical post hoc tests, mixing model output, and the assessment of niche occupation by LVF and BAT carnivores point to high levels of interspecific competition among large active carnivores, albeit some genera, such as the amphicyonid Magericyon and specially the hyaenid Lycyaena, seemed to avoid competition by taking prey from a more open habitat. Despite the drop in diversity and change in faunal components observed between the LVF and BAT assemblages, a high degree of resource and habitat competition is evident from stable isotope data.本研究通过稳定同位素分析（stable isotope analysis），对西班牙两处晚中新世遗址中的顶级捕食者（apex predators）的资源与栖息地利用模式展开探究：两处遗址分别为富恩蒂杜尼亚谷（Los Valles de Fuentidueña，约960万年前，简称LVF）与巴塔隆斯山（Cerro de los Batallones，约910万年前，简称BAT）。LVF与BAT所代表的时间窗口对现今伊比利亚哺乳动物区系的形成至关重要，该时段对应约9.5–8.5 Ma的瓦勒斯阶-图罗利安阶（Vallesian–Turolian）过渡期内的动物群更替事件与区域环境变化初始阶段，而此次环境变化与降水季节性增强密切相关。草食动物与肉食动物的δ¹³C、δ¹⁸O值表明，在LVF至BAT所覆盖的时间跨度内，植被覆盖（从林地向中生性C3草原转变）与水文状况均未出现显著变化。这意味着瓦勒斯阶-图罗利安阶界线附近记录的环境转变可能发生于更晚时期，因为LVF与BAT的测年结果与动物群更替事件的起始时间完全同步。从基于稳定同位素分析的捕食者-猎物评估视角来看，针对LVF与BAT遗址肉食动物的统计事后检验（post hoc tests）结果、混合模型（mixing model）输出数据，以及生态位占据情况评估均显示，大型活跃肉食动物间存在高强度的种间竞争；不过部分类群——如两栖犬科的马格里西翁犬属（Magericyon），尤其是鬣狗科的莱克亚纳鬣狗属（Lycyaena）——似乎通过在更为开阔的生境中获取猎物来规避竞争。尽管LVF与BAT的化石组合间存在物种多样性下降与动物群组成变化，但稳定同位素数据仍可证明二者存在高度的资源与栖息地竞争。