Reithrodontomys paradoxus Jones and Genoways, 1970 . Occas. Pap. W. Found. Vert. Zool., 2:12.
TYPE LOCALITY: Nicaragua, Carazo Dept., 3 mi NNW Diriamba, about 660 m .
DISTRIBUTION: Isolated records from SW Nicaragua and WC Costa Rica.
COMMENTS: Subgenus Aporodon, mexicanus species group. Morphologically closest to R. brevirostris; extent of distribution unknown. See Jones and Baldassarre (1982, Mammalian Species, 192).