Oligoryzomys nigripes (Olfers 1818)

[Oligoryzomys] nigripes (Olfers 1818), in: Eschwege, J. Brasilien, Neue Bibliothek. Reisenb., Vol. 15: 209.

Type Locality: Paraguay, Paraguarí Dept., Ybycui National Park, 85 km SSE Atyra (as restricted by neotype designation by Myers and Carleton, 1981:14).

Vernacular Names: Black-footed Colilargo.

Synonyms: Oligoryzomys tarsonigro (Fischer 1814) .

Distribution: E Paraguay, N Argentina, and Atlantic Forest region, C and SE Brazil (Rio Grande do Sul to Paraíba, interior to Goías and Distrito Federal; also Ilha Grande; see Andrades-Miranda et al., 2001 a, and Bonvicino and Weksler, 1998).

Conservation: IUCN – Lower Risk (lc).

Discussion: Neotype designated, diagnosis emended, and karyotype described (2n = 62, FN = 80) by Myers and Carleton (1981), who regarded Mus tarsonigro Fischer, 1814, as a nomen oblitum; further, they recommended that Mus longitarsus Rengger, 1830, which could apply to either O. microtis or O. nigripes, be considered a nomen dubium. Distributional extent complex; in SE Brazil, predominantly a sylvan animal whose range may penetrate drier Cerrado and Caatinga biomes along riparian forests (Bonvicino and Weksler, 1998); also found on offshore island, Ilha Grande, Rio de Janeiro (Pereira et al., 2001). Pattern of microgeographic variation in craniodental variables evaluated in E Paraná, Brazil (as Oryzomys nigripes), by Santos (1997). Relationship to forms such as delticola, eliurus, and longicaudatus warrants additional investigation (also see comments under O. delticola).