696.

Calaca’s White-tailed Mouse

Calassomys apicalis

French: Calassomys / German: Diamantina-Weil 3schwanzmaus / Spanish: Raton de cola blanca de Calaga

Taxonomy. Calassomys apicalis Pardinas et al., 2014, “ Brazil, Minas Gerais, Sempre Vivas National Park, 3-25 km by road NW Macacos, Pedreira do Gaio (19°57°50”S, 43°47°18°W, 1251 m asl).”

Calassomys apicalis is the type species of the genus. Monotypic.

Distribution. Known only from EC Brazil (Sempre Vivas National Park, Minas Gerais State).

Descriptive notes. Head-body 103-125 mm, tail 149-158 mm, ear 19-21 mm, hindfoot 25-29 mm; weight 29-55 g (mean 38:5 g). Calaca’s White-tailed Mouse is medium-sized, with moderately large ears; numerous and long mystacial vibrissae, the longest surpassing tips of ears when bent backward; and long tail, with entirely white distal tip of 2.5-5 cm and short terminal tuft of hair. Eyes are regularly sized, with conspicuous black eye-ring. There are numerous dark and white mystacial vibrissae. Upper lips are densely covered by white hairs. Ears are rounded, partially naked, covered internally and externally by short and delicate brown hair. Dorsal and ventral colors are subtly delimited with weak countershading. Dorsal fur has dark gray base and ocherous brown or yellowish brown tips; it is long (guard hairs c¢.15 mm) and soft; ventral fur is plumbeous gray, washed with white. Long tail is clearly longer than head-body length and bicolored dorso-ventrally—brown above, white below—except for distal 2.5-5 cm that is white all around, sparse apical tuft present conformed by white hairs of ¢.5-6 mm long. Manus is dorsally covered with short whitish hairs; claws are inconspicuous. Pesis enlarged and narrow; pedal dorsum sparsely covered by entirely whitish hair; plantar surface is naked. Chromosomal complementis 2n = 62, FN = 116.

Habitat. Rocky outcrops within the “campos rupestres,” an open physiognomy that characterizes plateaus and mountaintops in Sempre Vivas National Park, at elevations of 1100-1450 m.

Food and Feeding. Dental morphology of Calaca’s White-tailed Mouse suggests a diet mainly of seeds.

Breeding. No information.

Activity patterns. Little is know, but Calaca’s White-tailed Mouse is nocturnal. Anatomical traits of Calaca’s White-tailed Mouse such as morphology of plantar pads suggests a moderate climbing ability.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The IUCN Red List. Calaca’s White-tailed Mouse should probably be classified as Data Deficient.

Bibliography. Pardinas & Patton (2015), Pardinas, Lessa et al. (2014).