Opossums are members of the marsupial order Didelphimorphia endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North America in the Great American Interchange following the connection of North and South America.
The white-bellied woolly mouse opossum is a small pouchless marsupial of the family Didelphidae. It was formerly assigned to the genus Micoureus, which was made a subgenus of Marmosa in 2009. The specific epithet was given in honour of Constance Sladen, wife of the naturalist Percy Sladen. She funded the 1902 expedition which collected the type specimen.
The woolly mouse opossum or long-furred woolly mouse opossum, known locally as the cuíca, is a South American marsupial of the family Didelphidae. Its range includes central Colombia, Venezuela, French Guiana, Guyana, Suriname, eastern Peru, northern Bolivia, and northern Brazil. It was formerly assigned to the genus Micoureus, which was made a subgenus of Marmosa in 2009.
The delicate slender opossum is a small pouchless marsupial of the family Didelphidae that occurs in French Guiana, Guyana, Suriname, and adjacent Venezuela and Brazil. Marmosops pinheiroi, Marmosops bishopi and Marmosops juninensis had long been considered to represent the same species, until parvidens and pinheiroi were found in sympatry in French Guiana. This species is found in moist primary tropical rainforest at elevations up to 2000 m. It is nocturnal and partially arboreal, and feeds on insects and fruit.
The bushy-tailed opossum is an opossum from South America. It was first described by English zoologist Oldfield Thomas in 1912. It is a medium-sized opossum characterized by a large, oval, dark ears, fawn to cinnamon coat with a buff to gray underside, grayish limbs, and a furry tail. Little is known of the behavior of the bushy-tailed opossum; less than 25 specimens are known. It appears to be arboreal (tree-living), nocturnal and solitary. The diet probably comprises insects, eggs and plant material. This opossum has been captured from heavy, humid, tropical forests; it has been reported from Bolivia, Brazil, Colombia, Ecuador and Peru. The IUCN classifies it as least concern.
The bare-tailed woolly opossum is an opossum from South America. It was first described by Swedish zoologist Carl Linnaeus in 1758. The bare-tailed woolly opossum is characterized by a gray head, brown to gray coat, orange to gray underside and a partially naked tail. It is nocturnal and solitary; there is hardly any social interaction except between mother and juveniles and in mating pairs. The opossum constructs nests in tree cavities, and its litter size ranges from one to seven. Gestation lasts 25 days, and the juveniles exit the pouch after three months; weaning occurs a month later. The bare-tailed woolly opossum inhabits subtropical forests, rainforests, secondary forests, and plantations; its range extends from northern Venezuela to northeastern and southcentral Brazil. The IUCN classifies this opossum as least concern.
The brown four-eyed opossum is a pouchless marsupial of the family Didelphidae. It is found in different forested habitats of Central and South America, from Nicaragua to Brazil and northern Argentina, including southeastern Colombia, Paraguay and eastern Peru and Bolivia, at elevations from sea level to 1,500 m (4,900 ft). It is the only recognized species in the genus Metachirus, but molecular phylogenetics studies suggest that it should probably be split into several species. Population densities are usually low, and it is uncommon in parts of Central America. A density of 25.6/km2 (66/sq mi) was reported near Manaus, Brazil. Its karyotype has 2n = 14 and FN = 24.
Monodelphis is a genus of marsupials in the family Didelphidae, commonly referred to as short-tailed opossums. They are found throughout South America. As of January 2019, the most recently described species is M. vossi.
The agile gracile opossum, is an opossum species from South America. It is found in Argentina, Bolivia, Brazil, Colombia, Peru, Paraguay, and Uruguay.
The white-bellied slender opossum is a species of opossum from South America. It is found in Bolivia, Brazil, Ecuador and Peru.
The Brazilian slender opossum is an opossum species from South America. It is found in moist montane forest in the Atlantic Forest region of southeastern Brazil, including the states of Minas Gerais, Rio de Janeiro, São Paulo and Paraná. Its breeding may be fully semelparous, which is unusual for a mammal.
The yellow-sided opossum is an opossum species from South America. It is found in Argentina, Brazil and Uruguay. They have grey or black fur on their dorsal side with yellowish fur on the lateral side that continues down to the feet. They are the most mysterious of all the Monodelphis that is found specifically in the Pampean region or Pampa of Argentina. It is suspected to be a once-in-a-lifetime breeder as seen in a three-year observational study of one population in the marshy grasslands of the Pampean region. Maintaining their native grasslands is important for them to keep a stable population. They show sexual dimorphism in overall size: adult males are typically 100-150 g whereas adult females are 30-70 g.
The pygmy short-tailed opossum, scientifically named Monodelphis kunsi, is an opossum species from South America. M. kunsi is a marsupial from the family Didelphidae of the order Didelphimorphia. Although it is a marsupial, it lacks the characteristic pouch that is often associated with this order. It is found in Argentina, Bolivia, Brazil and Paraguay. M. kunsi is considered a smaller species within the family Didelphidae, which is why it is named a pygmy opossum. The young are referred to as 'joeys'. The females are referred to as 'Jill,' and the males 'jack'. It was thought to have been endangered in 2001, but has since been moved to least concern by the International Union for Conservation of Nature.
Marmosops is a genus of Neotropical opossums of the family Didelphidae. The genus was originally treated as a subgenus from the genus Marmosa rather than having their own classification. This was changed in 1989 by Gardner and Crieghton, who officially separated the group and made them their own genus. The mix-up between to genera Marmosa and Marmosops was common due to the similar appearances including size and other external features. However, the two groups differ significantly in their integument and in the arrangement of their skull and dentition. The dentition is similar in morphology between the two groups, with the exception of the deciduous lower third premolar varying from one genus to the next. The similarity between the two continues to cause the genus Marmosops to be frequently misidentified due to the lack of knowledge regarding the species along with the overlooked traits that help separate them from other opossums. The Marmosops are also commonly confused with the genus Gracilinanus, but this is quickly ruled out by a large number of differing characteristics. These differences include the arrangement of their digits, caudal scales, and the central hair on the scales changing from a three hairs per follicle to many more. This causes the hair of the Gracilinanus to be thicker and has also found to be heavily pigmented. The last group commonly confused with Marmosops is known as the genus Thylamys. These animals have a contrasting dorsal body pelage and the taxa are actually quite different.
Dorothy's slender opossum is a species of opossum in the family Didelphidae. It is found in Brazil and Bolivia. It is threatened by habitat loss.
Gracilinanus is a genus of opossum in the family Didelphidae. It was separated from the genus Marmosa in 1989, and has since had the genera Cryptonanus, Chacodelphys, and Hyladelphys removed from it.
Bishop's slender opossum is a small, arboreal marsupial opossum native to Brazil, Peru, and Bolivia. It somewhat resembles a placental rat or shrew.
The Junin slender opossum is a species of South American opossum in the family Didelphidae. It is known only from the valley of the Chanchamayu in Peru where it lives in Andean montane forests at elevations between 1460 and 2200 m. The species is threatened by destruction of its forest habitat as the area under cultivation in the region increases.
The spectacled slender opossum, also known as little spotted slender opossum is a species in the marsupial genus Marmosops from South America.
