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.

食肉目哺乳动物极少被纳入古环境重建（paleoenvironmental reconstructions）研究，究其核心原因，该类群在化石记录中保存体量稀少。不过，多变量统计建模可有效将特定解剖特征量化为环境预测指标。本研究以亲缘关系密切的食肉目类群——猫科（Felidae）为研究对象，通过分析其肱骨的形态变异，探究形态计量指标与生境类型之间的关联。我们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、去体型校正与比值法）开展分析，并探索了四种不同的生境适应性分类方案。开放生境、混合生境与封闭生境三类的划分标准，基于物种传统形态描述、分布范围及生物群栖息环境等依据确立。本研究通过线性判别分析完成了大量探索性工作，并纳入多件化石标本以开展古生态重建。尽管将样本按小型猫类与大型猫类类群分组可显著提升模型稳定性，但我们未发现不同形态计量指标或生境分类标准的预测能力存在显著差异。针对来自东非奥杜威峡谷（Olduvai Gorge）的三种长犬齿猫科动物：斯剑虎（Smilodon populator）、东方副剑齿虎（Paramachairodus orientalis）及恐猫未定种（Dinofelis sp.），本研究得出了具有重要学术价值的结论。研究推断，斯剑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，则被推断适配混合生境。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，较老的地层段（第一段，1.99~1.79 Ma）所涵盖的环境类型范围，较第二段与第五段更为广泛；后两段中存在大量适应开放生境的猫科动物化石。