Proechimys roberti Thomas

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 : 28-29

Proechimys roberti Thomas

Identification. This terrestrial spiny rat has a moderate-sized body and the tail is shorter than head and body. The dorsal pelage is reddish brown with a mixture of stiff and soft fur and the spines are relatively narrow. Ventral pelage is white. Juveniles have completely dark gray dorsal pelages, and one adult specimen (UFES 1388) had a pale buff colored dorsum and whitish tail and ears. Ears are grayish brown and distinctly larger than those of similar genera encountered in the area. The tail is bicolored and covered by thin hairs. Hind feet are narrow and elongate. Specimens from our Proechimys roberti series ( Fig. 17 ) agree in craniodental characters with the descriptions given by Patton (1987) and Weksler et al. (2001). The rostrum is tapered and the temporal region has no ridges. The floor of the infraorbital foramen is flat without nerve canal. The incisive foramen is oval or constricted posteriorly, and the palate is either flat or with small median ridges. The mesopterygoid fossa varies from pattern 2 (sensu Patton 1987, extending to the posterior half of M3) to pattern 3 (sensu Patton 1987, extending to the anterior half of M3). The counterfold pattern is 3-3-3-3 on upper molars and 3-2-2-2 on lower molars.

Measurements (n = 46): HB = 185–255, T = 118–168, HF = 42–53, E = 19–27, W = 165–411.

Distribution. This species occurs in the Cerrado of central Brazil and east Amazonia ( Woods & Kilpatrick 2005).

Natural history. Fifty-five individuals (43 adults and 12 juveniles) were captured in Tomahawk and Sherman traps placed on the ground of upland forests with dense undergrowth vegetation. All 18 adult males had scrotal testes and nine adult females were lactating in September 2006, June and October 2007, and September 2008. Vouchers (n = 21: 7ɗ 14Ψ): UFES 1388–1405, 1445 –1447.

Figures

FIGURE 17. Dorsal, ventral and lateral views of skull and mandible of Proechimys roberti (female, UFES 1396).