Reithrodon caurinus Thomas 1920

365. North-western Conyrat Reithrodon caurinus French: Reithrodon des Andes / German: Nordwestliche Kaninchenratte / Spanish: Rata conejo noroccidental Taxonomy. Reithrodon caurinus Thomas, 1920, “Otro Cerro, Catamarca [Argentina]. Alt. 3000 m.” Clarified by U. F. J. Pardinas and colleagues in 2007 as “an abandoned ranch in the southern end of the Sierra de Ambato, Capayan, Catamarca.” Reithrodon caurinus 1s resurrected for Reithrodon populations in north-western Argentina. Monotypic. Distribution. NW Argentina (JujuyTucuman, and Catamarca provinces). Descriptive notes. Head—body 127-149 mm, tail 94-99 mm, ear 24-28 mm, hindfoot 30-5-34-5 mm; weight 77-95 g. Reithrodon species are easily distinguishable from other sigmodontine rodents by their large heads, ears, and eyes, massive bodies, moderately short and haired tails, and short and blunt claws on manus and pes. Conspicuous bands of lighter pelage form a mask (piebald markings) around eyes and ears that usually decays in stored museum skins. Furis soft, luxurious, and dense. Tail is typically bicolored and densely haired but without an apical tuft. Long whitish hairs cover dorsal surfaces of manus and pes and ungualtufts surpasstips of claws. Reithrodon has four pairs of mammae. The North-western Conyratis strongly buffy, with whitish belly and nearly white tail. Dorsum is clay-colored and heavily lined with black ends to longer hairs. Sides are bufty, often ocherous buff, and rump is more or less this color. Venter is whitish, not sharply defined laterally, but almost entirely without buffy or cinnamon found in other species of Reithrodon; hairs are broadlyslaty at bases, except in inguinal region where they are wholly white. Anterior part of outer surfaces of ears (proectote) are blackish; posterior part of inner surfaces of ear (metentote) are buffy. Manus and pes are white; soles are poorly haired. Tail is white, with darker color of upper side restricted to narrow line. Habitat. Isolated treeless grasslands at elevations above 2000 m. At El Infiernillo (3043 m, Tucuman Province), the North-western Conyrat was recorded in an area of dense bunch grass, cut by numerous small rocky gullies. Food and Feeding. No information. Breeding. No information. Activity patterns. The North-western Conyrat is nocturnal and terrestrial. Movements, Home range and Social organization. Some North-western Conyrats were trapped in burrow systems of the caviomorph rodent Ctenomys (tuco-tucos). Status and Conservation. Not assessed on The IUCN Red List. Bibliography. Dalby (1974), Diaz & Barquez (1999, 2007), Jayat, Ortiz & Miotti (2008), Jayat, Ortiz, Teta et al. (2006), Mares et al. (1997), Ortiz & Jayat (2012), Pardinas & Galliari (2001), Pardinas, Galliari & Teta (2015), Thomas (1920b), Yepes (1935a).Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 413, DOI: 10.5281/zenodo.670714