Oligoryzomys microtis (Allen, 1916)

Velazco, Paúl M. & Patterson, Bruce D., 2019, Small Mammals Of The Mayo River Basin In Northern Peru, With The Description Of A New Species Of Sturnira (Chiroptera: Phyllostomidae), Bulletin of the American Museum of Natural History 2019 (429), pp. 1-69 : 51

Oligoryzomys microtis (Allen, 1916)

VOUCHER MATERIAL: El Diamante: 3 adult females ( MUSM 39283 , 39284 ; FMNH 203506 ) ; Tingana: 1 adult male ( FMNH 203676 ) ; Waqanki: 1 adult female ( MUSM 39282 ) ; see table 24 for measurements.

IDENTIFICATION: We consulted descriptions and measurements of Oligoryzomys microtis provided by Olds and Anderson (1987; as Oryzomys microtis ), Anderson (1997), Patton et al. (2000), Voss et al. (2001), Hice and Velazco (2012), Weksler and Bonvicino (2015b), and Pardiñas (2017b). No subspecies are currently recognized in O. microtis ( Weksler and Bonvicino, 2015b; Pardiñas, 2017b). Oligoryzomys microtis is characterized by the following characteristics: dorsal fur dull yellowish brown, finely lined with blacktipped hairs; ventral fur white; upper surfaces of feet thinly covered with light buffy brown hairs; ears small, brownish, and nearly naked; eight mammae; stapedial foramen with large opening, indicating carotid circulation pattern 2 ( Weksler and Bonvicino, 2015b; Pardiñas, 2017b). Our specimens conform to previous descriptions of the species, and measurements fall within the range of size variation previously documented.

REMARKS: The specimen collected at the Tingana location was caught at the edge of a renacal (flooded forest of Coussapoa trinervia ). All the other specimens were caught in cultivated areas. Lareschi and Velazco (2013) reported the mite Laelaps paulistanensis from our specimens.