Nectomys squamipes (Brants 1827)

[Mus] squamipes Brants 1827, Het Geslacht der Muizen: 138.

Type Locality: Brazil, São Paulo State, São Sebastião (as restricted by Hershkovitz, 1944:32).

Vernacular Names: Atlantic Forest Nectomys.

Synonyms: Nectomys aquaticus (Lund 1841); Nectomys brasiliensis (Pictet and Pictet 1844); Nectomys olivaceus Hershkovitz 1944; Nectomys pollens Hollister 1914; Nectomys robustus (Burmeister 1854) .

Distribution: SE Brazil (Pernambuco to Rio Grande do Sul), NE Argentina (Misiones Prov.), and E Paraguay.

Conservation: IUCN – Lower Risk (lc).

Discussion: Hershkovitz (1944) arrayed most nominal taxa of water rats as subspecies of N. squamipes, a polytypic view maintained by Cabrera (1961). Gardner and Patton (1976) intimated the mixed specific composition of " squamipes," and Reig (in Honacki et al., 1982; 1986) offered enumerations of valid species and probable synonymies. Formerly included apicalis, magdalenae, palmipes, and rattus (see those accounts). The narrower definition of N. squamipes now coalescing (that is, containing those populations with 2n = 56-59—Andrades et al., 2001 b; Barros et al., 1992; Bonvicino et al., 1996) corresponds to a species restricted to the Atlantic Forest region, overlapping with N. rattus in riverine settings of the Cerrado-Caatinga biomes. See Ernest (1986, Mammalian Species, 265).