Abstract Rhagomys is a genus of South American cricetids composed of three living species. They occur in eastern Andean and lowland tropical forests. Since description of this genus more than a century ago, it was treated as an enigmatic form within Sigmodontinae, varyingly thought to be allied to different suprageneric groups, with several scholars highlighting their presumptive autapomorphies. However, this morphologically based controversy was resolved with the advent of molecular data, indicating a weak affiliation to Thomasomyini. Here we resume the anatomical scrutiny of Rhagomys based on new evidence. New data, including CT-scan craniodental exploration and an ICAMER molar analysis, reinforce the uniqueness of this cricetid in the subfamily. In addition, we have enlarged and reworked the genetic data, composed of mitochondrial and nuclear markers, supporting not only the monophyly of Rhagomys, but also its resolution as a distinct branch of the sigmodontine radiation. To accommodate these results, we describe a new tribe for Rhagomys. The recognized clade is the most phenotypically differentiated of the Oryzomyalia and inaugurates a new arboreal morphotype. We hypothesize that Rhagomys has a set of anatomical features used to exploit understory resources by primarily insectivorous mice.

中文翻译：

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超多样性哺乳动物进化枝的形态差异：新热带蟋蟀的新形态类型和部落

摘要 Rhagomys 是南美蟋蟀的一个属，由三个现存物种组成。它们出现在安第斯山脉东部和低地热带森林中。自从一个多世纪前对该属的描述以来，它就被视为 Sigmodontinae 中的一种神秘形式，被认为与不同的超属群体有关，一些学者强调了他们推定的自拟态。然而，随着分子数据的出现，这种基于形态学的争议得到了解决，表明与 Thomasomyini 的联系较弱。在这里，我们根据新的证据恢复对 Rhagomys 的解剖学检查。新数据，包括 CT 扫描颅牙探查和 ICAMER 磨牙分析，强化了这种蟋蟀在亚科中的独特性。此外，我们扩大并重新处理了基因数据，由线粒体和核标记组成，不仅支持 Rhagomys 的单一系，而且支持其作为 sigmodontine 辐射的一个独特分支的分辨率。为了适应这些结果，我们为 Rhagomys 描述了一个新部落。公认的进化枝是稻瘟病菌中最具表型分化的，并开创了一种新的树栖形态类型。我们假设，Rhagomys 具有一组解剖学特征，用于主要是食虫小鼠利用林下资源。