Data from: Cats in the forest: predicting habitat adaptations from humerus morphometry in extant and fossil Felidae (Carnivora)

Mammalian carnivores are rarely incorporated in paleoenvironmental reconstructions, largely because of their rarity within the fossil record. However, multivariate statistical modeling can be successfully used to quantify specific anatomical features as environmental predictors. Here we explore morphological variability of the humerus in a closely related group of predators (Felidae) to investigate the relationship between morphometric descriptors and habitat categories. We analyze linear measurements of the humerus in three different morphometric combinations (log-transformed, size-free, and ratio), and explore four distinct ways of categorizing habitat adaptations. Open, Mixed, and Closed categories are defined according to criteria based on traditional descriptions of species, distributions, and biome occupancy. Extensive exploratory work is presented using linear discriminant analyses and several fossils are included to provide paleoecological reconstructions. We found no significant differences in the predictive power of distinct morphometric descriptors or habitat criteria, although sample splitting into small and large cat guilds greatly improves the stability of the models. Significant insights emerge for three long-canine cats: Smilodon populator, Paramachairodus orientalis, and Dinofelis sp. from Olduvai Gorge (East Africa). S. populator and P. orientalis are both predicted to have been closed-habitat adapted taxa. The false "sabertooth" Dinofelis sp. from Olduvai Gorge is predicted to be adapted to mixed habitat. The application of felid humerus ecomorphology to the carnivoran record of Olduvai Gorge shows that the older stratigraphic levels (Bed I, 1.99–1.79 Ma) included a broader range of environments than Beds II or V, where there is an abundance of cats adapted to open environments.

哺乳纲食肉目类群极少被纳入古环境重建研究，究其原因主要是其在化石记录中保存量稀少。不过，多变量统计建模可被成功用于将特定解剖特征量化为环境预测因子。本研究以亲缘关系密切的食肉目类群——猫科（Felidae）为研究对象，探究其肱骨的形态变异规律，以揭示形态计量学指标与生境类型之间的关联。我们针对肱骨的线性测量数据，采用三种不同的形态计量组合方式（对数转换、去体型校正以及比值法）进行分析，并探索了四种不同的生境适应类型划分方法。开阔生境、混合生境与封闭生境三类的划分标准，均基于物种的传统形态描述、分布范围以及生物群栖息环境特征。本研究通过线性判别分析开展了大量探索性分析，并纳入多件化石标本以开展古生态重建。尽管将样本划分为小型猫类与大型猫类类群可显著提升模型的稳定性，但我们并未发现不同形态计量指标或生境划分标准在预测能力上存在显著差异。针对采自东非奥杜威峡谷（Olduvai Gorge）的三种长犬齿猫类：斯米尔登剑齿虎（Smilodon populator）、东方副剑齿虎（Paramachairodus orientalis）以及恐猫未定种（Dinofelis sp.），本研究获得了关键研究发现。研究结果显示，斯米尔登剑齿虎与东方副剑齿虎均为适应封闭生境的类群；而奥杜威峡谷的假‘剑齿虎’——恐猫未定种则被推断为适应混合生境的类群。将猫科肱骨生态形态学方法应用于奥杜威峡谷的食肉目化石记录后发现，较早的地层段（第一地层段，Bed I，距今1.99~1.79百万年）所涵盖的环境类型比第二地层段（Bed II）与第五地层段（Bed V）更为多样，后两段中存在大量适应开阔生境的猫类化石。