Marmosops bishopi (Pine, 1981)

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 : 24-25

Marmosops bishopi

This appears to be the appropriate name for Bolivian specimens of the Marmosops parvidens group, of which we have examined eight examples from widely scattered localities in Beni, Cochabamba, La Paz, and Santa Cruz (fig. 10). These are all very small animals ( table 7) with much shorter molar series (LM ³ 5.8 mm) than any other Bolivian congener. The skulls have rounded supraorbital margins that lack distinct beading, shallow postorbital constrictions are dorsally visible, there are no palatine fenestrae, and the upper canines have small posterior accessory cusps. Although one adult male ( MSB 55843) has an almost­naked patch of skin and a streak of red­stained fur on the midline of the throat, two others ( CBF 7531 , LHE 1541 ) have no trace of a gular gland. All three adult males have well­developed, blade­like lateral carpal tubercles, and the scrotum is pale, with white fur and unpigmented skin. None of the females we examined had well­developed mammae, so it is not known whether or not this taxon has pectoral teats .

9 Because Anderson (1997) seldom cited museum catalog numbers, we consulted his card file of examined specimens (preserved in the AMNH Department of Mammalogy archives) to determine the empirical basis for mapped collection localities of Bolivian Marmosops ( Anderson, 1997: figs. 493–495).

There is noteworthy pelage color variation among the material at hand. All of the specimens we examined from Beni, Cochabamba, La Paz, and western Santa Cruz have dull reddish­brown dorsal fur, self­whitish ventral fur bordered by more­or­less distinct lateral zones of gray­based hairs, and unicolored tails. By contrast, the single available skin from eastern Santa Cruz ( LHE 1541 ) 10 has pale grayish­brown dorsal fur, self­cream ventral fur (without well­ defined lateral zones of gray­based hairs), and an indistinctly bicolored tail. Despite these pigmental differences, specimens from eastern Santa Cruz do not differ from the rest of our Bolivian material in other respects (e.g., measurements and qualitative craniodental traits), and partial cytochrome­ b sequences from representative exemplars ( LHE 1541 and AMNH 268938 ) differ by only about 3.8% (J.L. Patton, personal commun.) .

Specimens that we identify as Marmosops bishopi were included among the material that Anderson (1997) reported as M. impavidus (e.g., UMMZ 156014), M. noctivagus keaysi (USNM 579249), and M. parvidens (AMNH 268938).

BOLIVIAN SPECIMENS EXAMINED: Beni, 1 km E La Embocada (UMMZ 156014); Cochabamba, Cordillera de Mosetenes (CBF 7531); La Paz, Alto Río Madidi (USNM 579249), La Reserva (AMNH 268938); Santa Cruz, El Refugio (LHE 1541, 1553, 1556), San Rafael de Amboró (MSB 55843).