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 gray four-eyed opossum is an opossum species from Central and South America, ranging from southern Mexico to Peru, Bolivia and southwestern Brazil, at altitudes from sea level to 1600 m, but generally below 1,000 metres (3,300 ft). Its habitats include primary, secondary and disturbed forest. It is one of many opossum species in the order Didelphimorphia and the family Didelphidae.
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.
The southeastern four-eyed opossum is an opossum species native to South America. It is found in Atlantic Forest ecoregions, in Brazil, Paraguay and Argentina.
Anderson's four-eyed opossum is an opossum species from South America. It is found in Brazil, Colombia, Ecuador, Peru and Venezuela. Its dorsal fur is dark, with a black stripe, about 3–4 cm wide, going vertically down the midline of its back. Its dorsal fur is short, about 10 mm long. Its ventral fur is dark gray, but still distinctly lighter than the sides and dorsum. Its tail is furred for the first (approximately) 18% of its length, going from the base to the tip. Its species name "andersoni" was chosen to honor American scientific collector Malcolm Playfair Anderson.
The nine species in the genus Philander, commonly known as gray and black four-eyed opossums, are members of the order Didelphimorphia. Mature females have a well-developed marsupium. The tail appears to be hairless except for the proximal 5 or 6 cm, which has a few long hairs. The tail is slightly longer than the head-and-body length, and it is black for the proximal one half to two thirds of its length. The genus is closely related to Didelphis but the species of Philander are smaller than those of Didelphis. The genus formerly included Metachirus nudicaudatus, but this species lacks a pouch and so is now considered a separate genus. The common name comes from the white spots above the eyes, which can appear from a distance to be another set of eyes.
The Brazilian gracile opossum is a species of small opossum from Brazil.
The dwarf fat-tailed mouse opossum, also known as the velvety fat-tailed opossum is an opossum species from South America. It is endemic to Brazil, where it is found in cerrado and caatinga habitats. Its head-and-body length is about 141-212 mm, and its tail length is about 73-85 mm. Its diet is 44% arthropods; 75% of its diet consists of animals and animal products. Its ventral fur is entirely gray-based. Its hind foot is less than 14 mm, which is short for the genus.
Maria Nazareth Ferreira da Silva is a zoologist from Manaus, Brazil
Kalinowski's mouse opossum or the Peru gracile mouse opossum is a species of opossum in the family Didelphidae. It is found in Brazil, French Guiana, Guyana, and Peru. Its natural habitat is subtropical or tropical moist lowland forests at elevations up to 1000 m.
The common fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It occurs in Argentina, Bolivia, and Paraguay in chaco and Andean foothill habitats. Its head-and-body length is about 75 to 120 mm, and its tail length is about 90 to 134 mm. Its dorsal fur is brownish gray, and its ventral fur is yellowish to white. The legs and cheeks are the same color as the ventral surface. Its tail is sharply bicolored. A ring of faintly darker fur surrounds each eye. Its tail often lacks fat deposits, but does not always.
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.
The Didelphinae are a subfamily of opossums consisting of 15 genera and 123 species. Specimens have been collected throughout the Americas, but are predominant in South and Central America.
Karimi's fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is endemic to central and northeast Brazil, where it is found in the cerrado and caatinga at elevations from 300 to 1100 m. This opossum is crepuscular and mostly terrestrial; its omnivorous diet includes leaves, insects and small vertebrates. Its head-and-body length is about 95 millimeters, and its tail length is about 72 millimeters. It is very similar to T. pallidor. Its tail may be nonprehensile. The species is named after Iranian epidemiologist Y. Karimi. It is threatened by habitat destruction and fragmentation due to agriculture and ranching.
The deltaic four-eyed opossum or delta opossum is a species of opossum found in the Orinoco River delta region of Venezuela, South America, first described in 2006. It inhabits perennially flooded swamp forest or seasonally flooded marsh forest of the adjacent deltas of the Orinoco and nearby rivers. Its dorsal fur is gray. Its ventral fur is cream-colored, but is restricted by the hairs on the sides, which are gray at the base. Its ears are colored only along the margins. The spots above its eyes are small. The spots behind its ears are small and inconspicuous.
Mondolfi's four-eyed opossum is a South American species of opossum found in Colombia and Venezuela, first described in 2006. It inhabits foothills of the Cordillera de Mérida and those on the eastern side of the Cordillera Oriental at elevations from 50 to 800 m. Populations in the two ranges may represent distinct subspecies. It is named after the Venezuelan biologist Edgardo Mondolfi. It has short woolly fur with a pale cream-colored venter as well as large ears pigmented on only the distal half.
Olrog's four-eyed opossum is a South American species of opossum endemic to eastern Bolivia, first described in 2008 based on specimens collected in 1974. It inhabits the lowland Amazon rainforest, with an elevation range of 150 to 250 m. The species is named after Swedish-Argentine biologist Claes C. Olrog. It is sympatric with P. opossum, which it resembles. The two species differ in several ways, such as ventral fur color and condition of the zygomatic arch.
