The Elegant Fat-tailed Mouse Opossum (Thylamys elegans) is a species of opossum in the family Didelphidae. Its head-and-body length ranges from 106 to 121 millimeters. Its tail length ranges from 115 to 142 millimeters. Its tail is swollen (it stores fat in its tail) and has fine hairs all over it. Its fur color varies, but it usually ranges from light gray to light brown. The sides are lighter, and the ventral fur is white, possibly with gray or yellow mixed in. There is a dark patch surrounding each eye, extending towards the nose. Females have been reported to have nineteen nipple

Nipple

In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

s. Females give birth to around eight to twelve (up to fifteen) young per litter. In Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

, the breeding season is from September to March, producing about two litters. An elegant fat-tailed mouse opossum makes nests in various places. It eats mainly arthropod

Arthropod

An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

s and their larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e, but it also eats fruits, small vertebrates, and possibly carrion. It is found in Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

 and perhaps Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, at altitudes from sea level to 2500 m.