Necromys lasiurus (Lund)

Rocha, Rita G., Ferreira, Eduardo, Costa, Barbara M. A., Martins, Iracy C. M., Leite, Yuri L. R., Costa, Leonora P. & Fonseca, Carlos, 2011, Small mammals of the mid-Araguaia River in central Brazil, with the description of a new species of climbing rat, Zootaxa 2789, pp. 1-34 : 16

Necromys lasiurus (Lund)

Identification. This is a small-sized species with tail shorter than the head and body length. The dorsal pelage is dark gray brown and the fur has yellowish brown tips; ventral pelage varies from whitish to yellowish gray without a well-defined lateral line. Eyes have a cream periocular ring and ears are covered with small yellow hairs. The tail is bicolored. Front and hind feet are dark and the claws are covered by long ungual hairs.

Craniodental characters of N. lasiurus vouchers ( Fig. 7 ) agree with the description by Voss (1991). The rostrum is short and zygomatic notches are deep. The interorbital region converges anteriorly and has weakly beaded supraorbital margins. The incisive foramen is long, reaching the protocone of M1, and is parallel-sided with anterior part wider than the posterior. The palate is short, without conspicuous posterolateral pits. The alisphenoid strut is present, separating buccinator-masticatory and accessory oval foramina. Upper incisors are orthodont. Principal cusps of upper and lower molars alternate in anteroposterior position. Labial accessory root present in M1 and mesoloph is absent.

Measurements (n = 5): HB = 80–96, T = 62–73, HF = 21–24, E = 17–19, W = 21–31.

Distribution. This species occurs south of the Amazon River, from central Brazil to Bolivia, Paraguay and Argentina ( Musser & Carleton 2005), throughout open vegetations of Cerrado and transition areas between this biome and Atlantic Forest ( Bonvicino et al. 2008).

Natural history. Five adults of N. lasiurus were captured in pitfalls (n = 2) and in Sherman traps (n = 3) placed on the ground in Cerrado sensu strictu at FLV. Two males with scrotal testes and three females with open vaginas were trapped in September and October 2008.

Vouchers (n = 5: 2ɗ 3Ψ): UFES 1334–1338.

Figures

FIGURE 7. Dorsal, ventral and lateral views of skull and mandible of Necromys lasiurus (female, UFES 1337).