Marmosops, Matschie, 1916

VOSS, ROBERT S., TARIFA, TERESA & YENSEN, ERIC, 2004, An Introduction to Marmosops (Marsupialia: Didelphidae), with the Description of a New Species from Bolivia and Notes on the Taxonomy and Distribution of Other Bolivian Forms, American Museum Novitates 3466, pp. 1-40 : 31-32

Unidentified Marmosops

Among the Bolivian specimens we examined are three that we are unable to confidently identify with any of the taxa recognized in this report. Two (AMNH 275461, MSB 67021) were collected 7 km SE Ariruma at an elevation of 1750 m on the lower Andean slopes of western Santa Cruz department. Unlike Marmosops ocellatus , which occurs in the adjacent lowlands of Santa Cruz, these specimens have darker dorsal fur, paler (self­white) underparts, and lack distinct postorbital constrictions. They differ from M. impavidus by their grayer dorsal fur, by lacking lateral zones of gray­based ventral fur, and by lacking distinct postorbital constrictions. They differ from all of the forms herein referred to M. noctivagus by lacking interorbital beads. They differ from M. bishopi by having grayer dorsal pelage, well­de­ veloped palatine fenestrae, much larger teeth (LM = 6.7 mm), and by lacking accessory cusps on C1.

The other unidentified specimen is MSB 63275, a young adult female from the Río Limón at 1300 m on the lower Andean slopes of northeastern Chuquisaca. It has browner and somewhat paler dorsal fur than does the Río Ariruma material, and selfcream ventral fur with broad lateral bands of gray­based hairs (versus underparts entirely self­white). However , the crania of all three specimens are not dissimilar, and they differ from those of recognized Bolivian taxa by essentially the same characters .