Santamartamys rufodorsalis (J.A.Allen, 1899)

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Echimyidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 552-604 : 590-591

73.

Red Crested Tree-rat

Santamartamys rufodorsalis

French: Rat-épineux a créte rouge / German: Rotschopf-Baumratte / Spanish: Rata arboricola de dorso rojo

Other common names: Red Crested Soft-furred Spiny-rat

Taxonomy. Isothrix rufodorsalis J. A. Allen, 1899 ,

“Onaca, Santa Marta District,” Magdalena, Colombia .

Santamartamys rufodorsalis was formerly classified in the genera Echimys and Diplomys . Monotypic.

Distribution. N Colombia (Sierra Nevada de Santa Marta); it might occur in NW Venezuela.

Descriptive notes. Head—body 190 mm, tail 267 mm; weight 492 g. The Red Crested Tree-rat is bright rustred, with legs and sides pale yellow-orange, gray underfur, and white belly. Distinct crest of long bright red hairs is present on crown between ears. Sides and upper part of muzzle tip are yellow-gray, streaked with black. Mask of pale yellow-gray occurs between eyes, ears, and on rostrum, delimited dorsally by dark stripe of fur. Chest and throat are pale orange, and tip of chin is white. Its fur is soft, without any bristles or spines, having long, lax dorsal guard hairs. Dense woolly fur covers legs, ankles, and wrists. Vibrissae are short and do not extend beyond ears. Ears are short and naked, with tufts of long hairs emerging from inner surfaces. Like in species of Diplomys , the Red Crested Tree-rat has two pairs of lateral abdominal mammae along ventro-lateral side of body. Robusttail is c¢.140% of head-body length and densely clothed with 20 mm of rusty basal hairs, followed by large band of black and brown hairs covering scales for three-fifths of tail length and ending with pure white part. Hindfeet and front feet are brown above, washed with silvery gray color. There are no palmar or plantar tubercles, and pollex has a nail. Skull of the Red Crested Tree-rat is curved in dorsal profile, as in species of Diplomys , rostrum is short and broad. Similar to species of Diplomys , small auditory meatusis placed close to squamosal bone but has short auditory tube, anteriorly oriented. Auditory bullae are flattened and relatively small compared with skull length and merged with alisphenoid bone at shallow angles. Lateral process of supraoccipital is extremely short. Long bony bridge is present between foramen ovale and masticatory foramen. Condyloid process ofjaw is deep; shallow angle is present between sigmoid notch and angular and condyloid processes. Mandibular foramina are located in fossa downward on condyloid ridge. Pterygoid shelf is small. Lower incisors are strongly curved. Distinct maxillary and mandibular cheekteeth are rectangular and longer than wide. Tooth rows are long and bowed inward. Teeth differ from species of Diplomys , with only one separation between first two lophs of fourth upper premolar. Lophidsare still connected on lower molars and are very distinct compared with species of Diplomys .

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Habitat. Endemic in montane primary and secondary rainforests of the Sierra Nevada de Santa Marta, north-eastern Colombia at elevations of 680-2000 m.

Food and Feeding. There is no specific information available for this species, but the Red-Crested Tree-rat is likely folivorous.

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 Critically Endangered on The IUCN Red List. The Red-Crested Tree-rat was previously classified as Vulnerable, but the Critically Endangered status is a consequence of the decline known in the extent of occurrence, important fragmentation of the population, small area of occupancy, and degradation of habitat in this region. Additional ecological and field studies are needed to have a better estimate ofits distribution and area of occupancy. There are no data on abundance and survival capacities of the Red-Crested Tree-rat, but available records indicate that it is rare. It is only known from three specimens in the American Museum of Natural History and a potential unrecorded specimen in the Instituto de Investigacion Alexander von Humboldt in Colombia. One individual was observed and photographed at the El Dorado Eco Lodge after more than a century without confirmed records.

Bibliography. Allen (1899b), Eisenberg (1989), Emmons (1990, 1997a, 2005), Emmons & Patton (2015e), Woods & Kilpatrick (2005).

Figures

12. Broad-headed Spiny-rat (Clyomys laticeps), 13. Guiara (Euryzygomatomys spinosus), 14. White-spined Spiny-rat (Irinomys albispinus), 15. Elias’s Spiny-rat (Trinomys eliasi), 16. Rigid-spined Atlantic Spiny-rat (Trinomys paratus), 17. Yonenaga’s Spiny-rat (Trinomys yonenagae), 18. Elegant-spined Atlantic Spiny-rat (Trinomys setosus), 19. Moojen’s Spiny-rat (Trinomys moojeni), 20. Pau Brasil Spiny-rat (Trinomys mirapitanga), 21. Rio de Janeiro Spiny-rat (Trinomys dimidiatus), 22. Sao Paulo Spiny-rat (Trinomys thering), 23. Gracile Atlantic Spiny-rat (Trinomys gratiosus), 24. Sao Lourenco Punare (Thrichomys laurentius), 25. Jacobina Punare (Thrichomys inermis), 26. Lagoa Santa Punare (Thrichomys apereoides), 27. Pantanal Punare (Thrichomys pachyurus), 28. Foster’s Punare (Thrichomys fosteri), 29. Painted Tree-rat (Callistomys pictus), 30. Coypu (Myocastor coypus), 31. Armored Rat (Hoplomys gymnurus)

Distribution. N Colombia (Sierra Nevada de Santa Marta); it might occur in NW Venezuela.