Zygodontomys J. A. Allen, 1897 . Bull. Am. Mus. Nat. Hist., 9:38.

TYPE SPECIES: Oryzomys cherriei J. A. Allen, 1895 (= Oryzomys brevicauda J. A. Allen and Chapman, 1893).

COMMENTS: First revised by Hershkovitz (1962), then thought to include southern populations now allocated to Bolomys lasiurus (see Maia and Langguth, 1981; Reig, 1987; Voss and Linzey, 1981). Definition of genus emended and species taxonomy revised by Voss (1991a); Reig (in Reig et al., 1990a) listed four species as valid. Karyology summarized by Gardner and Patton (1976) and Reig et al. (1990a). Hershkovitz (1962) considered Zygodontomys a member of the phyllotine group, an association disputed by other studies (Hooper and Musser, 1964a; Olds and Anderson, 1989; Pearson and Patton, 1976). Unsettled phylogenetic position expressed as Sigmodontinae incertae sedis (Reig, 1984; Voss, 1991a).