Holochilus chacarius Thomas 1906

Holochilus chacarius Thomas 1906, Ann. Mag. Nat. Hist., ser. 7, 18: 446.

Type Locality: Paraguay, Concepción Dept., E Chaco, one "league" NW Concepción, 500 ft (152 m).

Vernacular Names: Chacoan Marsh Rat.

Synonyms: Holochilus balnearum Thomas 1906 .

Distribution: Paraguay and NE Argentina.

Conservation: IUCN – Lower Risk (lc).

Discussion: Considered distinct by Massoia (1980 a), who treated balnearum as a synonym; Reig (1986) mentioned balnearum as another good species. Highly variable in diploid (2n = 48-56) and fundamental numbers (Nachman, 1992 b; Nachman and Myers, 1989; Vidal et al., 1976). Nachman (1992 a) recognized Paraguayan samples (as H. brasiliensis chacarius) as karyotypically distinguishable and specifically distinct from Argentinian populations (as H. vulpinus).