Oligoryzomys andinus

Karyotype: 2n = 60 and FN = 70. Autosomal complement: six metacentric and submetacentric pairs (two large, one medium and three small), and 23 acrocentric pairs (one large and the remaining small). Sex chromosomes: X was a large acrocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 8, Fig. 3E).