Proechimys chrysaeolus (Thomas, 1898)

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 : 576

46.

Boyaca Spiny-rat

Proechimys chrysaeolus

French: Rat-épineux du Boyaca / German: Boyaca-Kurzstachelratte / Spanish: Rata espinosa de Boyaca

Taxonomy. Echimys chrysaeolus Thomas, 1898 ,

“Muzo, N of Bogota,” Cundinamarca, Colombia.

Proechimys chrysaeolus belongs to the trinitatisspecies group. It includes magdalenae as a synonym. Taxonomic relationships between typical chrysaeolus and magdalenae remain unresolved; these two taxa may represent valid races or even distinct species. Monotypic.

Distribution. N Colombia, lower Cauca and Magdalena valleys W of E Andes Range.

Descriptive notes. Head—body 210-220 mm,tail 145-160 mm; weight 370 g. The Boyaca Spiny-rat is medium-sized relative to other species of Proechimys . Dorsum is dark yellowish to reddish brown, speckled with black hairs on back;sides are only marginally paler than mid-back but abruptly contrasting with venter, which is white from chin to inguinal region. Broad and dark angle band from few white hairs on dorsal surfaces of hindfeet interrupts white inner thigh stripes. Hindfootvaries in dorsal color butis typically dark or may have silvery hairs across metatarsals; toes are always dark brown. All plantar pads are well developed, with thenar and hypothenar sub-equal in size. Tail is dark brown above and pale below, sparsely haired, and naked to the eye, with scale annuli forming distinct rings, more so than in most other species of Proechimys , with 10-13 annuli/cm. Pelage is stiff and bristly to the touch, with well-developed aristiform hairs averaging 20-22 mm in length and 0-9-1-1 mm in width, terminating with very short whip-like or blunt tip. Skull of the Boyaca Spiny-rat is robust, but long and narrow, with particularly elongated rostrum. Temporal ridge is absent or only weakly developed, extending onto anterior parietals from supraorbital ledge,if present. Incisive foramina are oval to teardrop in shape and taperslightly with weak posterolateral flanges extending onto anterior palate forming shallow groove; premaxillary part of septum is well developed, broad, and extendsat least one-half the length of opening; maxillary part may be broad or narrow but always contacts premaxillary part so that vomer is not visible in ventral view; and maxillary part of septum is non-keeled so that palate lacks median ridge. Floor of infraorbital foramen may be entirely smooth or with only moderately developed groove resulting from slight lateral flange. Mesopterygoid fossa is moderately narrow, with angle averaging 59° and depth penetrating to middle of M?, on average. Counterfold pattern of all maxillary cheekteeth is uniformly 3-3-3-3; that of the lower cheekteeth varies slightly because dP, typically has three folds or rarely four, M, always with three folds, and M, and M, have 2-3 folds in about equal frequencies. Counterfold formula is thus 3-3-3-3/3(4)— 3-2(3)-2(3). Baculum is long (averaging c.10 mm) but relatively broad (2-5-2-8 mm in width) and has bulbous base with median depression and slightly developed apical wings with median notch at distal end. It is similar in size and shape to other members of the trinitatisspecies group and also to baculum of the Pacific Spiny-rat ( P. decumanus ). Chromosomal complementis 2n = 32 and FN = 54.

Habitats. Primary rainforest at elevations of 50-900 m.

Food and Feeding. The Boyaca Spiny-rat forages on fruit, seeds, few arthropods, and leaves.

Breeding. There is no information available for this species.

Activity patterns. There is no specific information available for this species, but the Boyaca Spiny-rat is nocturnal and terrestrial.

Movements, Home range and Social organization. There is no specific information available for this species, but the Boyaca Spiny-rat is reportedly solitary.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Habitat of the type locality of the Boyaca Spiny-rat has been severely altered by agriculture, mining, and logging; these activities are widespread overits distribution. Additional studies on distribution, habitat, abundance, ecology, and threats to the Boyaca Spiny Spiny-rat are needed to properly access its conservation status.

Bibliography. Allen (1899a), Bueno et al. (1989), Eisenberg (1989), Emmons (1990, 1997a), Gardner & Emmons (1984), Hershkovitz (1948), Patton (1987), Patton & Gardner (1972), Patton & Leite (2015), Patton & Reig (1989), Thomas (1914), 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, lower Cauca and Magdalena valleys W of E Andes Range.