Reithrodontomyini. While Vorontsov (1959) arranged Onychomys as sole member of its own tribe, apart from Reithrodontomyini, a robust body of data now supports its close phyletic affinity with Peromyscus and related genera (Allard and Honeycutt, 1991; Carleton, 1980; Hooper and Musser, 1964b; Stangl and Baker, 1984b; Sullivan et al., 1995), in particular Osgoodomys (Engel et al., 1998), and recommends the synonymy of these two family-group taxa (Reithrodontomyini having line priority).

Revised by Hollister (1914), with later regional reviews by Engstrom and J. Choate (1979), Riddle and J. Choate (1986), and Van Cura and Hoffmeister (1966). Status of fossil forms (early Pliocene-Holocene) and affinity with living species evaluated by Carleton and Eshelman (1979). Chromosomal evolution among three species investigated by Baker et al. (1979), allozymic differentiation by Sullivan et al. (1986), and molecular relationships by Allard and Honeycutt (1991), Riddle and Honeycutt (1990), and Sullivan et al. (1995). Historical biogeography considered by Riddle and Honeycutt (1990) and Riddle (1995).