The leaf‐eared mouse, Phyllotis xanthopygus (Waterhouse 1837) is a widely distributed sigmodontine rodent in South America, with populations ranging from central Peru to southern Argentina and Chile. Previous morphological and molecular contributions have suggested that P. xanthopygus represents a species complex. In order to characterize and disclose this cryptic species complex, we perform a molecular genetic/phylogenetic analysis of representative samples across its geographical distribution. Phylogenetic analyses were based on sequences of cytochrome‐b gene (801 base pairs; n = 114 specimens) and analysed by maximum likelihood and Bayesian approaches. We also employed a Bayesian implementation of the Poisson tree processes (bPTP) as a unilocus species delimitation method. Results from our phylogenetic analyses retrieve eight well‐supported clades. Five of these clades belong to populations known as P. xanthopygus s.l., which were paraphyletic to the closely related species P. bonariensis, P. caprinus, and P. limatus, displaying strong genetic divergences (>8%). The (bPTP) analyses recovered ten species within P. xanthopygus s.l. plus related forms (i.e. P. bonariensis, P. caprinus, and P. limatus). Our results, coupled with chromosomal and morphological evidences, support the recognition of these clades at the species level and provide a new framework to characterize the leaf‐eared mice complex. Our study highlights the importance of integrative approaches in disentangling the biodiversity of Neotropical rodents.

中文翻译：

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Phyllotis xanthopygus复合体（Rodentia，Cricetidae）的隐密物种之间的亲缘关系。

叶耳鼠Phyllotis xanthopygus（Waterhouse 1837）是在南美广泛分布的乙草on鼠，种群范围从秘鲁中部到阿根廷南部和智利。先前的形态学和分子贡献表明黄腐疟原虫代表物种复合体。为了表征和揭示这种隐性物种复合体，我们对整个地理分布中的代表性样品进行了分子遗传/系统发育分析。系统发育分析基于细胞色素b基因的序列（801个碱基对；n = 114个样本），并通过最大似然法和贝叶斯方法进行分析。我们还采用了泊松树过程（bPTP）的贝叶斯实现方法作为单种群定界方法。系统发育分析的结果检索了八个支撑良好的进化枝。这些进化枝的五个属于称为群体P. xanthopygus SL，这是并系到密切相关的物种P. bonariensis，P. CAPRINUS，和P. limatus，显示很强的遗传分歧（> 8％）。该（BPTP）分析回收的十种P. xanthopygus SL加上相关表格（即P. bonariensis，P. CAPRINUS和P. limatus）。我们的结果，加上染色体和形态学证据，支持在物种水平上识别这些进化枝，并提供了表征叶耳小鼠复合物的新框架。我们的研究强调了整合方法在解散新热带啮齿动物生物多样性方面的重要性。