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.
Hylaeamys laticeps, also known as the Atlantic Forest oryzomys or the large-headed rice rat, is a species of rodent in the family Cricetidae.
Cerradomys subflavus, also known as the terraced rice rat or flavescent oryzomys, is a rodent species from South America in the genus Cerradomys. It is found in the states of Goiás, São Paulo, and Minas Gerais, Brazil. Populations in Bolivia, Paraguay, and elsewhere in Brazil that were previously placed in this species are now classified as various other species of Cerradomys.
Hylaeamys yunganus, also known as the Amazonian oryzomys or Yungas rice rat, is a species of rodent in the genus Hylaeamys of family Cricetidae. It is found in lowland tropical rainforest throughout Amazonia, in northeastern Bolivia, eastern Peru, eastern Ecuador, southeastern Colombia, southern Venezuela, Guyana, Suriname, French Guiana, and northern Brazil. A closely related species, Hylaeamys tatei, occurs only in a small area in eastern Ecuador. Both were previously placed in Oryzomys.
The transitional colilargo also known as the intermediate lesser grass mouse, is a species of rodent in the tribe Oryzomyini known only from two individuals found in the Federal District in Brazil. Although described as a link between oryzomyine and akodontine rodents and placed in its own genus, Microakodontomys, Weksler and coworkers dismissed it as an aberrant Oligoryzomys.
Nephelomys albigularis, also known as the white-throated oryzomys or Tomes's rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. Described in 1860, it was the first Nephelomys species to be discovered. It was originally described in the defunct genus Hesperomys as Hesperomys albigularis and considered related to the much smaller H. longicaudatus. By 1894, it was placed in Oryzomys, as Oryzomys albigularis, and associated with what is now Nephelomys meridensis. In the early 1960s, the scope of the species was considerably expanded to include most of the species that are now in Nephelomys, as well as a single name, boliviae, that is currently a synonym of Euryoryzomys nitidus. From 1976 on, several of these were reinstated as separate species.
Handleyomys alfaroi, also known as Alfaro's rice rat or Alfaro's oryzomys, is a species of rodent in the genus Handleyomys of family Cricetidae. It is found in Belize, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. It was previously included in Oryzomys as Oryzomys alfaroi. Its natural habitats are subtropical and tropical lowland or montane dry forests at elevations ranging from sea level to 2500 m.
Handleyomys chapmani, also known as Chapman's oryzomys or Chapman's rice rat, is a species of rodent in the genus Handleyomys of family Cricetidae. It is found only in Mexico. It was previously placed in Oryzomys as Oryzomys chapmani, but has been provisionally transferred to the genus Handleyomys pending the description of a new genus to contain it.
The Colombian rice rat, also known as the white-footed Handley's mouse is a species of rodent in the family Cricetidae occurring only in Colombia. It was previously included in Oryzomys, but closely resembles the dusky montane rat, and accordingly both species were placed in the new genus Handleyomys in 2002.
Euryoryzomys legatus, also known as the Tarija oryzomys or big-headed rice rat, is a species of rodent in the family Cricetidae. It now belongs to the genus Euryoryzomys, having previously been placed in Oryzomys. It is found in the eastern Andes of northwestern Argentina and southern Bolivia.
Nephelomys levipes, also known as the nimble-footed oryzomys or light-footed rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. It is found on the eastern slope of the Andes from southeastern Peru into west-central Bolivia in cloud forest at elevations from 1,800 to 3,200 metres. It occurs in the same general area as its congener N. keaysi, but at higher altitudes.
Handleyomys rhabdops, also known as the highland oryzomys or striped rice rat, is a species of rodent in the genus Handleyomys of family Cricetidae. It is nocturnal and is found in Guatemala and Mexico in montane forest at elevations from 1250 to 3250 m.
Handleyomys rostratus, also known as the long-nosed oryzomys, long-nosed rice rat, or rusty rice rat is a species of rodent in the genus Handleyomys of family Cricetidae. It is found in Belize, El Salvador, Guatemala, Honduras, Mexico, and Nicaragua. It is nocturnal and is found in forests at elevations above sea level to 1200 meters. The Handleyomys rostratus attains its highest level of development in south and Central America. High rates of deforestation and habitat destruction are the biggest threat to the Handleyomys rostratus.
Handleyomys saturatior, also known as the cloud forest oryzomys or cloud forest rice rat, is a species of rodent in the genus Handleyomys of family Cricetidae. It is found in Belize, El Salvador, Guatemala, Honduras, Mexico, and Nicaragua in cloud forest at elevations from 750 to 2500 m. It was previously placed in the genus Oryzomys.
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera, distributed from the eastern United States to the southernmost parts of South America, including many offshore islands. It is part of the clade Oryzomyalia, which includes most of the South American Sigmodontinae.
Aegialomys is a genus of oryzomyine rodents from the lowlands and mountains of western Peru and Ecuador, including the Galápagos Islands. The species in this genus have historically been placed in Oryzomys, but according to cladistic research, the genus is more closely related to a group containing, among others, Nectomys and Sigmodontomys, than to Oryzomys. The generic name Aegialomys means "coastal mouse" in Ancient Greek and references the mostly coastal occurrence of the genus.
Euryoryzomys macconnelli, also known as MacConnell's rice rat or MacConnell's oryzomys, is a rodent species from South America. It is found in Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela, where it lives in lowland tropical rainforest. It was formerly placed in the genus Oryzomys, as Oryzomys macconnelli, but in 2006 it was reclassified as the type species of the new genus Euryoryzomys.
Hylaeamys is a genus of South American oryzomyine rodents found principally in humid forested areas east of the Andes. The species in this genus have historically been placed in Oryzomys. They are most closely related to Euryoryzomys, Transandinomys, Nephelomys, Oecomys, and Handleyomys, and most closely resemble species of the former two genera. They are distinguished from members of Euryoryzomys by all-dark or indistinct two-tone tail coloration, from members of Transandinomys by having shorter whiskers above their eyes that do not extend posteriorly behind their ears, and in both cases by differences in carotid circulation. The genus is named after hylaea, the term used by Humboldt for the lowland South American rainforests that are the main habitat of the genus.
Handleyomys is a genus of Central and South American rodents in the tribe Oryzomyini of family Cricetidae. It was first described in 2002 to include two species from the Colombian Andes which were previously included in distinct and unrelated genera, Aepeomys and Oryzomys, but which turned out to be closely related. Later, in 2006, six other species were provisionally added from Oryzomys; these are expected to be placed in new genera in the future.
In some rodents, squamae are small tubercles resembling scales on the sole of the hindfeet. Among oryzomyine rodents, their development is variable; most have well-developed squamae, but in others they are indistinct or entirely absent. Delomys sublineatus and Peromyscus maniculatus also have squamae.
