Phaenomys Thomas 1917

Phaenomys Thomas 1917, Ann. Mag. Nat. Hist., ser. 8, 20: 196.

Type Species: Oryzomys ferrugineus Thomas 1894

Species and subspecies: 1 species:

Species Phaenomys ferrugineus (Thomas 1894)

Discussion: Sigmodontinae incertae sedis per Smith and Patton (1999) or Oryzomyini sensu lato per Reig (1981). Another of the SE Brazilian endemics whose systematic relationships are minimally understood. Bonvicino et al. (2001) reported on a recently collected specimen, documenting its karyotype (2n = 78, FN = 114), redescribing the taxon’s morphology, and comparing it with Andean Thomasomyini and other Atlantic Forest thomasomyine-like genera. The authors noted that morphological characters reinforce the plesiomorphic nature of the genus, thereby offering little insight to relationships, while the chromosomal complement demonstrates affinity with species of Delomys .