The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. Their distribution includes much of the New World, but the genera are predominantly South American, such as brucies. They invaded South America from Central America as part of the Great American Interchange near the end of the Miocene, about 5 million years ago. Sigmodontines proceeded to diversify explosively in the formerly isolated continent. They inhabit many of the same ecological niches that the Murinae occupy in the Old World.
Neacomys minutus, also known as the minute neacomys, the small bristly mouse, or the minute spiny mouse, is a rodent species from South America in the genus Neacomys. It is found in Brazil.
The lesser Wilfred's mouse is a species of South American rodents of the family Cricetidae. It was first described by Wilfred H. Osgood under the name Thomasomys pictipes, then into the genus Wilfredomys, and now known as Juliomys pictipes. The lesser Wilfred's mouse is endemic to northeastern Argentina and southeastern Brazil. Its physical appearance ranges from dark brown to light orange coloration and the typical size is small to medium. This species is arboreal, spending most of its time trees and living in the local forests at altitudes from sea level to 2000 m. Currently, this species is listed as Least Concern by the IUCN, but, threats include livestock farming, ranching, and wood harvesting.
Gardner's climbing mouse is a rodent species from South America. It is found in western Brazil, southeastern Peru and northeastern Bolivia. It is an uncommon, arboreal species, but faces no particular threats so the International Union for Conservation of Nature has rated it as being a "least-concern species".
The white-footed climbing mouse is a species of South American rodent found in Bolivia, Brazil, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela. It is the type species of the genus and the type location was the lower eastern slopes of the Andes in central Peru.
Scolomys ucayalensis, also known as the long-nosed scolomys or Ucayali spiny mouse is a nocturnal rodent species from South America. It is part of the genus Scolomys within the tribe Oryzomyini. It is found in Brazil, Colombia, Ecuador and Peru in various different habitats in the Amazon rainforest.
The Brazilian arboreal mouse is a South American rodent species of the family Cricetidae. It is found in the Atlantic Forest of southeast Brazil, often close to bamboo thickets. It can be distinguished from Rhagomys longilingua, the only other species in its genus, by the absence of spines among the hair. Formerly believed to be extinct after no sightings were recorded for over 100 years, the species has since been found in four localities. However, it is nowhere common, and all of these are forest fragments, and ongoing deforestation threatens the species' survival. For these reasons, the International Union for Conservation of Nature has assessed its conservation status as being "vulnerable".
The spotted bolo mouse or Ecuadorian akodont is a species of rodent in the family Cricetidae. It is known from Ecuador and may also occur in Colombia. Little is known of its status and range.
The fossorial giant rat is a species of rodent in the family Cricetidae. It is found in Argentina and Brazil but was determined extinct following a recent assessment of the conservation status of Sigmodontine rodents. Its natural habitat is assumed to be dry savanna, but there have been no ecological details reported.
Microryzomys altissimus, also known as the Páramo colilargo or highland small rice rat, is a species of rodent in the genus Microryzomys of family Cricetidae. It is found in Colombia, Ecuador, and Peru, but the Colombian segment may be a separate species.
Microryzomys minutus, also known as the montane colilargo or the forest small rice rat, is a species of rodent in the genus Microryzomys of family Cricetidae. It is found in Bolivia, Colombia, Ecuador, Peru, and Venezuela, but these populations may represent more than one species.
Transandinomys bolivaris, also known as the long-whiskered rice rat, is a rodent in the family Cricetidae. It is found in humid forest from northeastern Honduras to western Ecuador, up to 1,800 m (5,900 ft) above sea level. Since it was first described in 1901 from Ecuador, six scientific names have been introduced for it, but their common identity was not documented until 1998 and the species has long been known under the name Oryzomys bombycinus, described from Panama in 1912. The name Oryzomys bolivaris was used before it was moved to the new genus Transandinomys with Transandinomys talamancae in 2006.
The smoky mouse is a species of rodent in the family Muridae native to southeastern Australia. It was first described in 1934 and its species name is Latin for "smoky". As its name suggests, it is a grey-furred mouse, darker grey above and paler smoky grey below. Mice from the Grampians are larger and a darker more slate-grey above. It has a black eye-ring and dark grey muzzle. The feet are light pink, and the ears a grey-pink. The tail is longer than the mouse's body, and is pink with a brownish stripe along the top. Mice from east of Melbourne average around 35 grams and have 107 mm long bodies with 116 mm long tails, while those from the Grampians are around 65 grams and have 122 mm long bodies with 132 mm long tails.
Coues's climbing mouse is a species of rodent in the family Cricetidae. It is found in Colombia, Ecuador, Peru, Trinidad and Tobago, and Venezuela. It is named in honour of the American zoologist Elliott Coues who studied birds and small mammals.
Scolomys melanops, also known as the short-nosed scolomys, South American spiny mouse, Ecuadorian spiny mouse, or gray spiny mouse, is a species of rodent in the genus Scolomys of family Cricetidae. It is a forest mouse and was thought to be endemic to Ecuador but it is now known to have a wider distribution, being also present in part of Peru.
The golden Oldfield mouse or golden thomasomys is a species of rodent in the family Cricetidae. It is found in Colombia, Ecuador, Peru, and Venezuela. Both the common and genus name commemorate the British zoologist Oldfield Thomas who worked at the Natural History Museum, London and studied South American rodents.
Thomasomys ucucha, also known as the ucucha thomasomys, is a rodent in the genus Thomasomys of the family Cricetidae. It is known only from high altitude forest and grassland habitats in the Cordillera Oriental of Ecuador. Seven other species of Thomasomys live in the same areas. First collected in 1903, T. ucucha was formally described as a new species in 2003 and most closely resembles T. hylophilus, which occurs further to the north. The species is listed as "vulnerable" in the IUCN Red List as a result of habitat destruction.
The Andean porcupine or Quichua porcupine is a species of rodent in the family Erethizontidae. It is found in the Andes of northern Ecuador and Colombia as well as in Panama. This porcupine is little known, but is probably arboreal, nocturnal and solitary like its relatives. The species is thought to be uncommon to rare and the population decreasing. It is threatened by deforestation, habitat fragmentation and agriculture.
