We describe a new species of woolly mouse opossum from northwestern Amazonia, Marmosa jansae, based on museum specimens previously misidentified either as M. germanaThomas, 1904, or as M. reginaThomas, 1898. Instead of being closely related to either of those species, M. jansae appears to be the sister taxon of M. perplexaAnthony, 1922, a trans-Andean species previously synonymized with M. phaea Thomas, 1899. We redescribe M. perplexa, which inhabits critically endangered evergreen and semideciduous forests in southwestern Ecuador and northwestern Peru. We also redescribe M. germana, an Amazonian species that has long been synonymized with M. regina, but which molecular analyses now suggest is the sister taxon of a trans-Andean species complex that includes M. alstoni (Allen, 1900). These results substantially clarify the long-confused taxonomy of woolly mouse opossums (subgenus Micoureus), provide new examples of sister-group relationships between upper-Amazonian and trans-Andean taxa, and raise interesting questions about congeneric diversity in northwestern Amazonia, where as many as six species of Marmosa might occur sympatrically.

中文翻译：

---

Didelphid有袋动物属Marmosa的修订本第3部分。来自西方亚马逊的新物种，重新命名为M. perplexa Anthony，1922年和M. germana Thomas，1904年

我们根据博物馆标本先前描述为误认为德国玛托马斯·托马斯（M. germanaThomas）（1904年）或里贾纳·M。reginaThomas（1898年）的博物馆标本，描述了来自西北亚马逊地区（Marmosa jansae）的一种新的羊毛小鼠负鼠物种。 jansae似乎是Perplexa安东尼（1922年）的姊妹分类群，Anthony是早先与M. phaea Thomas的同义词的跨安第斯物种，我们重新描述了Perplexa，栖息于厄瓜多尔西南部和秘鲁西北部极度濒危的常绿和半落叶林中。 。我们还重新描述了德国马来亚树（M. germana），这是一个长期以来一直与里贾斯山（M. regina）同义的物种，但现在的分子分析表明，它是包括阿尔斯通山（M. alstoni）在内的跨安第斯山脉物种群的姊妹分类群（Allen，1900）。