Lundomys Voss & Carleton 1993

Monotypic genus represented by L. molitor (Winge 1887), records of extant specimens were from southern South America, predominantly from Uruguay (Voss & Carleton 1993; Prado & Percequillo 2013).

Karyotype: 2n = 52 and FN = 58. Autosomal complement: four metacentric pairs (three large and one small), and 21 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium submetacentric; Y, a small metacentric. Heteromorphism of the X chromosome was reported due to different sizes of short arm. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomal pairs, but was almost absent on the three large metacentric pairs. The X chromosome presented a pericentromeric heterochromatic block. The Y chromosome presented a whole heterochromatic arm. G-banding was also performed (Freitas et al. 1983, pp. 14, Fig. 1).