Microryzomys altissimus (Osgood, 1933) . Field Mus. Nat. Hist. Pubi., Zool. Ser., 20:5.

TYPE LOCALITY: Peru, Pasco Dept., La Quinua, mountains north of Cerro de Pasco, 11,600 ft .

DISTRIBUTION: High Andes of Colombia, Ecuador, and Peru.

SYNONYMS: chotanus, hylaeus .

COMMENTS: Diagnosed as a subspecies of Oryzomys minutus but elevated to species by Hershkovitz (1940), who named two additional subspecies. Subspecific arrangement followed by Cabrera (1961) but none retained by Carleton and Musser (1989).