Phyllotis Waterhouse 1837 is one of the most studied genera of South American cricetid rodents. As currently understood, it includes 20 small to medium-sized species of predominantly rocky habitats. Among them, populations of the yellow-rumped leaf-eared mouse, traditionally referred to P. xanthopygus (Waterhouse 1837), are the most widely distributed, extending from central Peru to southern Chile and Argentina. Based mostly on molecular evidence, previous studies suggested that P. xanthopygus constitutes a species complex, being characterized by geographically structured and genetically divergent clades. In this work, we compare the molecular phylogenetic hypothesis for populations distributed on the eastern slopes of the central Andes with morphometric evidence using univariate and multivariate analyses. Quantitative morphological and molecular evidence suggests that at least four nearly cryptic species of the P. xanthopygus complex occur from southern Bolivia to west-central Argentina. Three of these taxa have available names; one of them, P. caprinus, is currently recognized to the species level; the other two, the clades of P. x. posticalis-P. x. rupestris and P. vaccarum, are both recognized as subspecies of P. xanthopygus. The remaining taxon represents a new species distributed in the west-central Andes of Argentina. We discuss our morphological results in the light of other sources of evidence (e.g. qualitative and quantitative state characters, genetic and phylogenetic studies, and cytogenetic data) and name the new species as P. pehuenche, honouring the original native people that historically inhabited west-central Andes of Argentina.

中文翻译：

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安第斯山脉中部的 Phyllotis xanthopygus 复合体（啮齿目，仓鼠科），一个新物种的系统学和描述

Phyllotis Waterhouse 1837 是南美仓鼠科研究最多的属之一。据目前所知，它包括 20 种中小型物种，主要栖息在岩石栖息地。其中，传统上称为P. xanthopygus (Waterhouse 1837)的黄腰叶耳鼠种群分布最广，从秘鲁中部延伸到智利南部和阿根廷。以前的研究主要基于分子证据，表明P. xanthopygus构成一个物种复合体，其特征是地理结构和遗传分化的进化枝。在这项工作中，我们使用单变量和多变量分析将分布在安第斯山脉中部东坡的种群的分子系统发育假设与形态测量证据进行了比较。定量的形态学和分子证据表明，从玻利维亚南部到阿根廷中西部，至少有四种近乎隐秘的P. xanthopygus复合体。其中三个分类群有可用的名称；其中之一，P。 caprinus，目前被确认为物种级别；另外两个，P. x的进化枝。posticalis-P。X。rupestris和P. vaccarum, 都被认为是P. xanthopygus 的亚种。剩余的分类群代表了分布在阿根廷中西部安第斯山脉的一个新物种。我们根据其他证据来源（例如定性和定量状态特征、遗传和系统发育研究以及细胞遗传学数据）讨论我们的形态学结果，并将新物种命名为P. pehuenche，以纪念历史上居住在西部的原始土著人。阿根廷中部安第斯山脉。