Populations of amphibians are experiencing severe declines worldwide. One group with the most catastrophic declines is the Neotropical genus Atelopus (Anura: Bufonidae). Many species of Atelopus have not been seen for decades and all eight Central American species are considered “Critically Endangered”, three of them very likely extinct. Nonetheless, the taxonomy, phylogeny, and biogeographic history of Central American Atelopus are still poorly known. In this study, the phylogenetic relationships among seven of the eight described species in Central America were inferred based on mitochondrial DNA sequences from 103 individuals, including decades-old museum samples and two likely extinct species, plus ten South American species. Among Central American samples, we discovered two candidate species that should be incorporated into conservation programs. Phylogenetic inference revealed a ladderized topology, placing species geographically furthest from South America more nested in the tree. Model-based ancestral area estimation supported either one or two colonization events from South America. Relaxed-clock analysis of divergence times indicated that Atelopus colonized Central America prior to 4 million years ago (Ma), supporting a slightly older than traditional date for the closure of the Isthmus. This study highlights the invaluable role of museum collections in documenting past biodiversity, and these results could guide future conservation efforts. An abstract in Spanish (Resumen) is available as supplementary material.

中文翻译：

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根据线粒体DNA序列推断，高度濒临灭绝的丑角蛙（Atelopus）向中美洲的近期快速辐射。

两栖动物的数量正在全球范围内急剧下降。灾难性下降最大的一组是新热带属Atelopus（Anura：Bufonidae）。几十年来没有出现过许多Atelopus物种，中美洲所有八种都被认为是“极度濒危”，其中三种极有可能灭绝。尽管如此，中美洲美洲狼的分类学，系统发育和生物地理史仍然鲜为人知。在这项研究中，根据来自103个个体的线粒体DNA序列（包括数十年前的博物馆样本和两个可能的灭绝物种，以及十个南美物种）推断了中美洲描述的八个物种中的七个之间的系统发育关系。在中美洲样本中，我们发现了两个应纳入保护计划的候选物种。系统发育学推论揭示了一个阶梯状的拓扑结构，使地理上距离南美最远的物种更多地嵌套在树上。基于模型的祖传面积估计支持南美的一两次殖民化事件。散度时间的宽松时钟分析表明，Atelopus在四百万年前（马）之前在中美洲定居，支持的地峡封闭日期比传统日期稍早。这项研究强调了博物馆藏品在记录过去的生物多样性方面的宝贵作用，这些结果可以指导未来的保护工作。提供西班牙语摘要（摘要）作为补充材料。