Thylamys

• Mesopotamian Fat-tailed Opossum Thylamys citellus

  

  This mouse opossum is recorded in a habitat mosaic in northeastern Argentina. Its taxonomy has been debated.

• Elegant Fat-tailed Mouse Opossum Thylamys elegans

  

  Its tail stores fat and changes in thickness by season with food availability. The coat is tricolored: darker on the back, paler on the sides, and cream-colored underneath.

• Karimi's Fat-tailed Mouse Opossum Thylamys karimii

  

  Karimi's fat-tailed mouse opossum has a thick tail whose size changes with seasonal food availability. Juveniles were captured in both wet and dry seasons, suggesting it might breed year-round.

• Paraguayan Fat-tailed Mouse Opossum Thylamys macrurus

  

  This small opossum is known from eastern Paraguay and adjacent central-western Brazil. Its mid-back is darker, becoming paler toward the flanks and belly.

• Pallid Fat-tailed Opossum Thylamys pallidior

  

  The pallid fat-tailed opossum is a small marsupial of dry habitats and high-elevation grasslands. It stores fat near the base of its tail and is mainly terrestrial, though it can climb shrubs and small trees.

• Dry Chaco Fat-tailed Opossum Thylamys pulchellus

  

  This small opossum is recorded in northern Argentina. Argentina’s 2019 assessment lists localities across several provinces, chiefly in the Chaco region.

• Dwarf Fat-tailed Mouse Opossum Thylamys velutinus

  The velvety fat-tailed opossum has been recorded in Brazil’s Cerrado and has a tail whose thickness changes seasonally.

• Thylamys fenestrae

  This small marsupial is recorded from the Pampas and Espinal regions of Argentina. Its dorsal fur is brown, with a thin brown ring around each eye. Fecal samples from caldén woodland in La Pampa contained many arthropods, especially larvae and ants.

• Chacoan Fat-tailed Opossum Thylamys pusillus

  This opossum lives in dry lowlands of central South America. Its back is darker than its sides and white underside, and it stores fat in its tail.

• Argentine Fat-tailed Mouse Opossum Thylamys sponsorius

  Its back, flanks, and belly have three distinct color zones. It lives in eastern Andean montane and seasonally dry forests; the genus's fat-storing tail changes in thickness with seasonal food availability.

• Tate's Fat-tailed Mouse Opossum Thylamys tatei

  This opossum has a three-colored coat and a tail that fattens with seasonal food availability. Its sparse records are from Ancash and Lima in central Peru.

• Buff-bellied Fat-tailed Mouse Opossum Thylamys venustus

  The Buff-bellied Fat-tailed Mouse Opossum is a small marsupial found from central Bolivia to northern Argentina in the Andes. It stores fat in its tail and is recorded in forest and seasonally dry forest.

• Pallid Fat-tailed Opossum Thylamys pallidior

  The pallid fat-tailed opossum is a small marsupial of dry habitats and high-elevation grasslands. It stores fat near the base of its tail and is mainly terrestrial, though it can climb shrubs and small trees.

• Elegant Fat-tailed Mouse Opossum Thylamys elegans

  Its tail stores fat and changes in thickness by season with food availability. The coat is tricolored: darker on the back, paler on the sides, and cream-colored underneath.

• Karimi's Fat-tailed Mouse Opossum Thylamys karimii

  Karimi's fat-tailed mouse opossum has a thick tail whose size changes with seasonal food availability. Juveniles were captured in both wet and dry seasons, suggesting it might breed year-round.

• Dwarf Fat-tailed Mouse Opossum Thylamys velutinus

  The velvety fat-tailed opossum has been recorded in Brazil’s Cerrado and has a tail whose thickness changes seasonally.

• Paraguayan Fat-tailed Mouse Opossum Thylamys macrurus

  This small opossum is known from eastern Paraguay and adjacent central-western Brazil. Its mid-back is darker, becoming paler toward the flanks and belly.

• Dry Chaco Fat-tailed Opossum Thylamys pulchellus

  This small opossum is recorded in northern Argentina. Argentina’s 2019 assessment lists localities across several provinces, chiefly in the Chaco region.

• Mesopotamian Fat-tailed Opossum Thylamys citellus

  This mouse opossum is recorded in a habitat mosaic in northeastern Argentina. Its taxonomy has been debated.