Zygodontomys Allen 1897

The genus Zygodontomys comprises two species, the monotypic Z. brunneus (Thomas 1898), and the polytipic Z. brevicauda (Allen & Chapman 1893) (that includes Z. b. brevicauda, Z. b. cherriei (Allen 1895), and Z. b. microtinus (Thomas 1894)) (Voss 1991). The genus occurs in unforested landscapes from the Pacific coast and foothills of eastern Costa Rica through Panama, Colombia, Venezuela, Guyana, Suriname, French Guiana, and Brazil north of the Amazon. Zygodontomys also occurs on adjacent continental-shelf islands (Trinidad and Tobago) where it may occupy forest as well as non-forest habitats. Z. brunneus was known only from the intermontane valleys of Colombian Andes and occurs sympatrically with Z. brevicauda that was more widespread, with known records from eastern Colombia throughout the Llanos, the savannas of the upper Rio Branco in Brazil, Suriname, French Guiana and Guyana (Voss 1991; Prado & Percequillo 2013). All cytogenetic data available for the genus was presented on Table 11, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 22.