Quintela Fernando Marques, Gonçalves Gislene Lopes, Althoff Sérgio Luiz, Sbalqueiro Ives Jose, Oliveira Luiz Flamarion Barbosa, De Freitas Thales Renato Ochotorena
Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Biologia Animal, Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil; Email: unknown.
Universidade Federal do Rio Grande do Sul, Departamento de Genética, Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil Instituto de Alta Investigación, Universidad de Tarapacá, Antofagasta 1520, Arica, Chile.; Email: unknown.
Zootaxa. 2014 Jun 3(3811):207-25. doi: 10.11646/zootaxa.3811.2.3.
A new species of swamp rat of the genus Scapteromys from the Meridional Plateau of Southern Brazil is described. Morphological, molecular, and karyological analysis support the recognition of the new species, distinct from S. aquaticus and S. tumidus. Scapteromys sp. nov. is significantly smaller than the congeneric taxa considering most of the external and craniometric measurements and the pelage is conspicuously grayer and darker. It can be distinguished from S. tumidus by the laterally extended thenar pad of the manus and the parallel edges of the hamular process of the pterygoid, and from S. aquaticus by a grayer and darker pelage and smaller values of most external and craniometric measurements. Karyological analysis indicated a difference in chromosome numbers across the distributional range: 2n=34 and 2n=36. A total of 11 haplotypes were found along the range of the new species within the biogeographic province of Araucaria angustifolia Forest. Strongly supported substructure was found within the new taxon, resulting in two reciprocally monophyletic clades.
描述了一种来自巴西南部 meridional 高原的新物种——斯氏水鼠属沼泽鼠。形态学、分子学和核型分析支持该新物种的认定，它与水生斯氏水鼠和肿胀斯氏水鼠不同。考虑到大多数外部和颅骨测量数据，新物种斯氏水鼠明显小于同属分类群，其皮毛明显更灰且更暗。它可以通过手部大鱼际垫横向延伸以及翼状骨钩状突边缘平行来与肿胀斯氏水鼠区分，通过更灰且更暗的皮毛以及大多数外部和颅骨测量数据较小值来与水生斯氏水鼠区分。核型分析表明在其分布范围内染色体数目存在差异：2n = 34 和 2n = 36。在南洋杉森林生物地理省内新物种分布范围内共发现 11 个单倍型。在新分类单元内发现了得到有力支持的亚结构，形成了两个相互单系的分支。
