Nesoryzomys Heller 1904

Nesoryzomys Heller 1904, Proc. California Acad. Sci., 3: 241.

Type Species: Nesoryzomys narboroughi Heller 1904

Species and subspecies: 4 species:

Species Nesoryzomys darwini Osgood 1929

Species Nesoryzomys fernandinae Hutterer and Hirsch 1979

Species Nesoryzomys indefessus (Thomas 1899)

Species Nesoryzomys swarthi Orr 1938

Discussion: Oryzomyini . Realigned as a subgenus of Oryzomys by Ellerman (1941), following the comments of Goldman (1918). Morphological, genic, and karyological information, however, sustains the generic separation of Nesoryzomys (Beaufort, 1963; Gardner and Patton, 1976; Patton and Hafner, 1983; Smith and Patton, 1999) and intimates that the group is an old Galapagos immigrant, originating ca. 3-3.5 million years ago (see Patton and Hafner, 1983). See Key and Heredia (1994) and Dowler et al. (2000) for recent assessments of conservation status, commensal rodent introductions, and natural history of populations on the various islands.