Salinoctomys loschalchalerosorum, Mares, Braun, Barquez & Diaz, 2000

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Octodontidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 536-541 : 539

4.

Chalchalero Viscacha Rat

Salinoctomys loschalchalerosorum

French: Octodon des Chalchaleros / German: Chalchaleros-Viscacharatte / Spanish: Rata vizcacha de Los Chalchaleros

Taxonomy. Salinoctomys loschalchalerosorum Mareset al., 2000 ,

“26 km SW Quimilo, Departamento Chamical, La Rioja Province, Argentina, (30° 02’ 43.4” S, 65° 31’ 13.4” W; elevation 581 m. ”

R. M. Barquez and colleagues in 2002 treated it as Tympanoctomys based on morphological characteristics, howeverit lacks of a formal description. C. A. Woods and C. W. Kilpatrick in 2005 and M. H. Gallardo and colleagues in 2007 have continued to recognize Salinoctomys as a valid genus. This last revision has been followed here. Morphological analyses suggest that Salinoctomys , which is not represented in any molecular analysis, is member of the desert-adapted clade ( Octomys [ Tympanoctomys + Pipanacoctomys ]), with a sister relationship with Pipanacoctomys . Monotypic.

Distribution. W Argentina , known only from the type locality in NE La Rioja Province.

Descriptive notes. Head-body 144-156 mm, tail 111-119 mm, ear 17 mm, hindfoot 28-30 mm. The Chalchalero Viscacha Rat is medium-sized. It has large and inflated auditory bullae. Pelage is brownish black dorsally and white ventrally. Tail is long (more than 75% of head-body length) with black tuft. Whitish to pale brownish hairs cover forefeet and hindfeet. Buccal bristles are present, but they are not well developed. Karyotype is unknown.

Habitat. Peri-saline shrublands associated with the Salinas Grandes salt flat at elevations of 500-600 m. The Chalchalero Viscacha Ratlives in a burrow system restricted to a narrow band of halophytic plants thatlies between bare salt flat and dense thornscrub of cacti, trees, and shrubs, typical of the Gran Chaco.

Food and Feeding. The Chalchalero Viscacha Rat specializes on halophytic vegetation and seems to forage mainly on Heterostachys ritteriana ( Amaranthaceae )—often most abundant in the immediate vicinity of its burrow system. It has been found in food stores in burrows.

Breeding. A pregnant Chalchalero Viscacha Rat with two embryos was collected in July.

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 Critically Endangered on The IUCN Red List. Extent of occurrence of the Chalchalero Viscacha Rat is less than 100 km?, and its area of occupancy is less than 10 km? All known individuals are in a single location, and extent and quality of its habitat continues to decline.

Bibliography. Barquez et al. (2002), Gallardo et al. (2007), Mares et al. (2000), Ojeda & Bidau (2013h), Woods & Kilpatrick (2005).

Figures

On following pages: 4. Chalchalero Viscacha Rat (Salinoctomys loschalchalerosorum); 5. Common Viscacha Rat (Octomys mimax); 6. Mountain Degu (Octodontomys gliroides); 7. Bridges's Degu (Octodon bridgesii); 8. Pacific Degu (Octodon pacificus); 9. Coastal Degu (Octodon lunatus); 10. Common Degu (Octodon degus); 11. Porter's Rock Rat (Aconaemys porteri); 12. Chilean Rock Rat (Aconaemys fuscus); 13. Sage’s Rock Rat (Aconaemys sage), 14. Coruro (Spalacopus cyanus).

Distribution. W Argentina , known only from the type locality in NE La Rioja Province.