57. Robust Tuco-tuco Ctenomys tuconax French: Tuco-tuco robuste / German: Robuste Kammratte / Spanish: Tuco tuco robusto Taxonomy. Cienomys tuconax Thomas, 1925, “Concepcion, 500 m,” Departamento Concepcion, Tucuman, Argentina, 27°20’ S, 63° 35° W. Ctenomys tuconaxis not classified in any species group. Chromosomal complement is 2n = 58-61 and FN = 80, and sperm is simple asymmetric. Monotypic. Distribution. NW Argentina (Tucuman Province), two disjunct populations in the Nevados de Aconquija. Descriptive notes. Total length up to 330 mm; weight c¢.600 g. The Robust Tucotuco is among the largest and most robust species of Ctenomys. Dorsum is uniformly dark chestnut, lacking darkened median line. Under parts are paler, but in some individuals, color approaches cinnamon. Head has similar color, with no special markings, although top of head can be slightly darker and chin paler. Tail is pale brown. Skull is very large, similar in size to individuals of the Andean Tuco-tuco (C. optimus). Shape of the Robust Tuco-tuco resembles that of the Andean Tuco-tuco. Nasals are medium-sized, not markedly narrowed posteriorly. Zygomatic arches are robust but not much expanded laterally. Bullae are not particularly developed, less inflated than in the Andean Tuco-tuco. Upper incisors are broad, heavy, and slightly proodont. Habitat. Yungas ecoregion at elevations of 262-3000 m. Food and Feeding. There is no information available for this species. Breeding. There is no information available for this species. Activity patterns. There is no information available for this species. Movements, Home range and Social organization. There is no information available for this species. Status and Conservation. Classified as Data Deficient on The IUCN Red List. Bibliography. Bidau (2006, 2015), Medina et al. (2007), Reig & Kiblisky (1969).

Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Ctenomyidae, pp. 498-534 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on page 531, DOI: 10.5281/zenodo.6588177