Thylamys sponsorius (Thomas, 1921)

Russell A. Mittermeier & Don E. Wilson, 2015, Didelphidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 129-186 : 178-179

86.

Argentine Fat-tailed Opossum

Thylamys sponsorius

French: Opossum dArgentine / German: Argentinien-Fettschwanzbeutelratte / Spanish: Marmosa coligruesa de Argentina

Other common names: Argentine Fat-tailed Mouse Opossum, Argentine Thylamys

Taxonomy. Marmosa elegans sponsoria Thomas, 1921 ,

“ Sunchal , 1200 m,” Sierra de Santa Barbara , Jujuy, Argentina.

This species is monotypic.

Distribution. S Bolivia (Tarijja) and NW Argentina (Jujuy, Salta, Tucuman, and Catamarca).

Descriptive notes. Head-body 8.6-11.9 cm, tail 12.5-15.4 cm; weight 15-5-62 g. The Argentine Fat-tailed Opossum has brownish-gray dorsal fur, with typical tricolored pattern of species of Thylamys , and is paler on body sides. Head is colored as dorsum, but facial fur is paler, with faint mid-rostral stripe, and there are thin, dark eye-rings. Tail length is ¢.135% of head—body length, and tail is slightly bicolored and can become incrassated (enlarged with stored fat). Ventral fur is gray-based, yellowish or white, and chin and throat are often yellowish or white, occasionally with whitish patches on chest, but usually whitish throughout. Forefeet and hindfeet are grayishwhite, and ears are fuscous. Females lack a pouch, and number of mammae is unknown. The Argentine Fat-tailed Opossum has a 2n = 14, FN = 20 karyotype, with four pairs of biarmed and two pairs of acrocentric autosomes, and with a small acrocentric X-chromosome. The Y-chromosome is absent in somatic cells.

Habitat. Dry thornscrub and shrub forests at elevations of 515-3750 m.

Food and Feeding. There is no specific information available for this species, but storage of fat in the tail of the Argentine Fat-tailed Opossum has been observed in May-July.

Breeding. A female Argentine Fat-tailed Opossum with a single young attached to a nipple was captured in December, and another lactating female, without any attached young, was captured in February.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Argentine Fat-tailed Opossum has a wide distribution, presumably large overall populations, and it also occurs in several protected areas throughout its distribution.

Bibliography. Braun, Mares & Stafira (2004), Braun, Van Den Bussche et al. (2005), Creighton & Gardner (2007c), Flores et al. (2000), Giarla et al. (2010), Palma et al. (2014), Tate (1933).

Figures

76. Patagonian Opossum (Lestodelphys halli), 77. Karimi’s Fat-tailed Opossum (Thylamys karimii), 78. Dwarf Fat-tailed Opossum (Thylamys velutinus), 79. Elegant Fat-tailed Opossum (Thylamys elegans), 80. Pallid Fat-tailed Opossum (Thylamys pallidior), 81. Tate's Fat-tailed Opossum (Thylamys tatei), 82. Mesopotamian Fat-tailed Opossum (Thylamys citellus), 83. Dry Chaco Fat-tailed Opossum (Thylamys pulchellus), 84. Chacoan Fat-tailed Opossum (Thylamys pusillus), 85. Paraguayan Fat-tailed Opossum (Thylamys macrurus), 86. Argentine Fat-tailed Opossum (Thylamys sponsorius), 87. Buff-bellied Fat-tailed Opossum (Thylamys venustus), 88. Bishop's Slender Opossum (Marmosops bishop), 89. Junin Slender Opossum (Marmosops juninensis), 90. Delicate Slender Opossum (Marmosops parvidens), 91. Pantepui Slender Opossum (Marmosops pakaraimae), 92. Pinheiro’s Slender Opossum (Marmosops pinheiroi), 93. Handley’s Slender Opossum (Marmosops handleyi), 94. Gray Slender Opossum (Marmosops incanus), 95. Brazilian Slender Opossum (Marmosops paulensis), 96. Neblina Slender Opossum (Marmosops neblina), 97. Tschudi’s Slender Opossum (Marmosops impavidus), 98. Spectacled Slender Opossum (Marmosops ocellatus), 99. Creighton’s Slender Opossum (Marmosops creightoni), 100. White-bellied Slender Opossum (Marmosops noctivagus), 101. Narrow-headed Slender Opossum (Marmosops cracens), 102. Dusky Slender Opossum (Marmosops fuscatus), 103. Panama Slender Opossum (Marmosops invictus)

Distribution. S Bolivia (Tarijja) and NW Argentina (Jujuy, Salta, Tucuman, and Catamarca).