ABSTRACT Species of Neacomys are small cricetid rodents that occur in forested habitats of Central and South America, from eastern Panama to central Bolivia and central/western Brazil. In order to assess species diversity of this poorly known genus, we obtained cytochrome b gene sequences from the most comprehensive taxonomic and geographic sampling analyzed to date. We also conducted morphological analyses on a large series of specimens housed in 15 museums, including types of 10 out of 14 nominal taxa. Our analyses of the genetic data recovered 17 lineages clustered in four distinct clades. Among these lineages, 11 correspond to species currently recognized as valid, and the remaining six are putative new species. In southeastern Amazonia—the geographical scope of this report—four undescribed species were discovered, three of which are named herein: Neacomys marajoara, sp. nov., from the Island of Marajó, Pará state; Neacomys vossi, sp. nov., restricted to the Tapajós center of endemism (between the Tapajós and Xingu rivers); and Neacomys xingu, sp. nov., restricted to the Xingu center of endemism (between the Xingu and Araguaia/Tocantins rivers). The new species can be discriminated from other Neacomys species by the morphology of the nasal bones, zygomatic plate, interorbital region, subsquamosal fenestra, paraoccipital process, incisive foramina, auditory bullae, anterocone and anteroloph of the first upper molar, carotid circulation pattern, and karyotype. Our results substantially improve our understanding of the genus Neacomys by providing morphological, morphometric, and novel molecular insights about these poorly known rodents and demonstrate that the diversity of small Amazonian mammals is still poorly known, even in the relatively accessible southeastern part of the biome.

中文翻译：

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新热带多刺小鼠的系统学，Neacomys Thomas 属，1900 年（啮齿目：仓鼠科），来自亚马逊东南部，对三种新物种的描述

摘要 Neacomys 种是小型鼠科啮齿动物，分布于中美洲和南美洲的森林栖息地，从巴拿马东部到玻利维亚中部和巴西中/西部。为了评估这个鲜为人知的属的物种多样性，我们从迄今为止分析的最全面的分类学和地理采样中获得了细胞色素 b 基因序列。我们还对 15 个博物馆中的大量标本进行了形态学分析，包括 14 个名义分类群中的 10 个类型。我们对遗传数据的分析恢复了聚集在四个不同进化枝中的 17 个谱系。在这些谱系中，11 个对应于目前公认有效的物种，其余 6 个是推定的新物种。在亚马逊东南部——本报告的地理范围——发现了四种未描述的物种，其中三个在此命名： Neacomys marajoara, sp。11 月，来自帕拉州马拉若岛；Neacomys vossi, sp. 11 月，仅限于塔帕若斯特有的中心（在塔帕若斯河和新古河之间）；和 Neacomys xingu, sp。11 月，仅限于辛古特有的中心（在辛古和阿拉瓜亚/托坎廷斯河之间）。新种可以通过鼻骨、颧骨、眶间区、鳞状下孔、枕旁突起、切牙孔、听大泡、第一上磨牙的前锥体和前锥体、颈动脉循环模式和其他 Neacomys 物种的形态与其他 Neacomys 物种区分开来。核型。我们的结果通过提供形态学、形态测量学、