Peruvian Woolly Mouse Opossum

description

DESCRIPTION: The dorsal pelage of Marmosa parda is dull brownish gray (near Ridgway’s Citrine Drab or Grayish Olive), with little tonal variation in the material we examined; at midback the fur ranges in length from 12 to 15 mm. The ventral fur is almost completely gray based, except on the chin and groin, which have self-yellowish or - buffy fur; additionally, a very narrow median streak of self-yellowish fur is present in some specimens. The tail seems to be slightly more than 130 % of head-and-body length, judging from the few available specimens measured by the American method; it is covered with short fur for only about 25 mm or less at the base, and the exposed caudal skin is completely dark (brownish in dried specimens) without any bold whitish markings. The manus and pes are covered dorsally with pale hairs in most specimens, but a few have indistinctly darker metacarpal pelage. Mature adult skulls of Marmosa parda are larger and more robust than those of M. rapposa in same-sex comparisons (fig. 13, table 8). However, these taxa are otherwise cranially similar, with short, wide rostrums; broadly flaring zygomatic arches; and well-developed postorbital processes. In ventral

A Revision Of The Didelphid Marsupial Genus Marmosa Part 2. Species Of The Rapposa Group (Subgenus Micoureus)

description

HABITATS: Nothing has been recorded about the habitats occupied by this species, but the typical vegetation of the eastern Andean slopes of central Peru between about 1000 and 2000 m is premontane or montane rainforest.

A Revision Of The Didelphid Marsupial Genus Marmosa Part 2. Species Of The Rapposa Group (Subgenus Micoureus)

discussion

COMPARISONS: Comparisons of Marmosa parda with M. rapposa have already been provided, so it only remains to compare this species with its sister taxon, M. rutteri. These species are externally similar, but the dorsal fur is typically somewhat longer in parda (≥ 12 mm) than in rutteri (in which it is usually <12 mm). Additionally, the tail appears to be relatively shorter in parda than in rutteri, although this is hard to assess with measurements obtained in the field by collectors using different protocols. Lastly, the ventral fur is more extensively gray based in most specimens of parda than it is in most specimens of rutteri. Although Tate (1933: 83) claimed that parda and rutteri were not distinguishable cranially, the clearest distinction between these taxa is the consistent, bilateral presence of large palatine fenestrae in parda and the absence, unilateral presence, or reduced size of these openings in rutteri. REMARKS: Tate (1931) originally described Marmosa parda as a subspecies of M. germana, but M. germana is a distantly related taxon (fig. 6) that has short postprotocristae and lacks palatine fenestrae and postcingulids. Specimens that we refer to M. germana are only kn

A Revision Of The Didelphid Marsupial Genus Marmosa Part 2. Species Of The Rapposa Group (Subgenus Micoureus)

distribution

DISTRIBUTION AND SYMPATRY: The material we refer to Marmosa parda is all from the upper Río Huallaga drainage between about 1000 and 2000 m in the departments of Huánuco and La Libertad, Peru (fig. 17). We are not aware that this species occurs sympatrically with any other member of the subgenus Micoureus.

A Revision Of The Didelphid Marsupial Genus Marmosa Part 2. Species Of The Rapposa Group (Subgenus Micoureus)