ABSTRACT We studied the phylogeny, biogeography, and diversification of suboscine passerines in the genus Scytalopus (Rhinocryptidae), a widespread, species-rich, and taxonomically challenging group of Neotropical birds. We analyzed nuclear (exons, regions flanking ultraconserved elements) and mitochondrial (ND2) DNA sequence data for a taxonomically and geographically comprehensive sample of specimens collected from Costa Rica to Patagonia and Brazil. We found that Scytalopus is a monophyletic group sister to Eugralla and consists of 3 main clades roughly distributed in (1) the Southern Andes, (2) eastern Brazil, and (3) the Tropical Andes and Central America. The clades from the Southern Andes and eastern Brazil are sister to each other. Despite their confusing uniformity in plumage coloration, body shape, and overall appearance, rates of species accumulation through time in Scytalopus since the origin of the clade in the Late Miocene are unusually high compared with those of other birds, suggesting rapid non-adaptive diversification in the group. We attribute this to their limited dispersal abilities making them speciation-prone and their occurrence in a complex landscape with numerous barriers promoting allopatric differentiation. Divergence times among species and downturns in species accumulation rates in recent times suggest that most speciation events in Scytalopus predate climatic oscillations of the Pleistocene. Our analyses identified various cases of strong genetic structure within species and lack of monophyly of taxa, flagging populations which likely merit additional study to clarify their taxonomic status. In particular, detailed analyses of species limits are due in S. parvirostris, S. latrans, S. speluncae, the S. atratus complex, and the Southern Andes clade.

中文翻译：

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新热带山地鸟类的神秘辐射 Scytalopus tapaculos (Rhinocryptidae) 的系统学、生物地理学和多样化

摘要我们研究了 Scytalopus (Rhinocryptidae) 属亚羽雀科的系统发育、生物地理学和多样化，这是一个分布广泛、物种丰富且在分类学上具有挑战性的新热带鸟类群。我们分析了从哥斯达黎加到巴塔哥尼亚和巴西收集的标本的分类学和地理综合样本的核（外显子、超保守元素侧翼区域）和线粒体 (ND2) DNA 序列数据。我们发现 Scytalopus 是 Eugralla 的单系群姐妹，由 3 个主要分支组成，大致分布在 (1) 南安第斯山脉、(2) 巴西东部和 (3) 热带安第斯山脉和中美洲。来自安第斯山脉南部和巴西东部的进化枝是彼此的姐妹。尽管它们在羽毛颜色、体型和整体外观上的一致性令人困惑，自中新世晚期起源以来，Scytalopus 物种随时间的积累率与其他鸟类相比异常高，表明该群体的快速非适应性多样化。我们将此归因于它们有限的传播能力，使它们易于形成物种，并且它们出现在具有促进异域分化的众多障碍的复杂景观中。物种间的分化时间和近来物种积累率的下降表明 Scytalopus 中的大多数物种形成事件早于更新世的气候振荡。我们的分析确定了物种内强大的遗传结构和缺乏分类群单一性的各种情况，标记了可能值得进一步研究以澄清其分类地位的种群。特别是，