| At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae) are recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes. Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832; "colilargo" or the long-tailed pygmy rice rat; 2n = 56), which ranges from 27° to approximately 51° S, and O. magellanicus (Bennet, 1836; Magellanic pygmy rice rat; 2n = 54), south of 51° S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the southern Patagonia of Chile, we report the results of small mammal samplings in six localities. We karyotyped 28 specimens and we also sequenced the hypervariable mtDNA region I in 22 individuals,... |
