TYPE MATERIAL AND TYPE LOCALITY: BMNH 53.8.29.18, the lectotype (designated by Thomas, 1888a), consists of the skin and skull of an adult male collected at Valparaíso (33.03° S, 71.63° W), Valparaíso region, Chile.

SYNONYMS: coquimbensis Tate, 1931; soricinus Philippi, 1894 (but see Remarks).

DISTRIBUTION: Thylamys elegans is endemic to Chile, where recent sequencing studies suggest that it ranges from about 21° S (in Tarapacá) to almost 36° S (in Maule), and from near sea level to about 1700 m (Palma et al., 2014; Boric-Bargetto et al., 2016). However, there are historical records of this species from as far south as Angol (37.80° S, 72.72° W) in the Araucanía region based on specimens seen by Tate (1933) and Greer (1965).

REMARKS: See Giarla et al. (2010) for an emended description and morphological comparisons of Thylamys elegans with congeneric taxa. Despite much taxonomic attention, this species remains problematic in several respects, some of which were discussed by Boric-Bargetto et al. (2016) and Giarla and Voss (2020b). A recent, geographically comprehensive analysis of mtDNA sequence data (Boric-Bargetto et al., 2021) suggests that the southernmost populations currently recognized as T. elegans might be a distinct species, for which T. soricinus could be the appropriate binomen if the diagnostic pelage traits mentioned by Pine (1979) and Giarla et al. (2010) were confirmed by examination of sequenced specimens. In that event, and if Philippi’s holotype —last seen by Osgood (1943) —cannot be found, then a neotype should be designated to fix the application of this name.

Phylogenetic analyses of multilocus sequence datasets have consistently recovered Thylamys elegans in a clade that also includes T. pallidior and T. tatei (see Giarla et al., 2010; Díaz-Nieto et al., 2016a; Amador and Giannini, 2016).