Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (O. palustris) of the United States and O. couesi of Mexico and Central America—are widespread; the six others have more restricted distributions. The species have had eventful taxonomic histories, and most species were at one time included in the marsh rice rat; additional species may be recognized in the future. The name Oryzomys was established in 1857 by Spencer Fullerton Baird for the marsh rice rat and was soon applied to over a hundred species of American rodents. Subsequently, the genus gradually became more narrowly defined until its current contents were established in 2006, when ten new genera were established for species previously placed in Oryzomys.
Cerradomys marinhus, also known as Marinho's rice rat, is a rodent species from South America. It is found in Minas Gerais, Brazil. It was formerly known as Oryzomys marinhus, but was transferred to the new genus Cerradomys in 2006.
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.
Oecomys bicolor, also known as the white-bellied oecomys or bicolored arboreal rice rat, is a species of rodent in the genus Oecomys of family Cricetidae. It has a wide distribution in the Amazon biome, occurring in northwestern Brazil, northern Bolivia, eastern Peru, eastern Ecuador, eastern Colombia, much of Venezuela, Guyana, Suriname, and French Guiana, and extends into eastern Panama, but it may contain more than one species.
Oecomys cleberi, also known as Cleber's oecomys or Cleber's arboreal rice rat, is a species of rodent in the genus Oecomys of family Cricetidae. Known only from the Federal District in Brazil, its taxonomic status relative to O. concolor and O. paricola is unresolved.
Oecomys concolor, also known as the unicolored oecomys, unicolored rice rat, or unicolored arboreal rice rat, is a species of rodent in the genus Oecomys of family Cricetidae. It is found in tropical rainforest in the Amazon biome, but its range is poorly documented; it has been recorded in northwestern Brazil, southeastern Colombia, and southern Venezuela.
The mamore arboreal rice rat,, also known as the Mamore oecomys is an arboreal species of rodent in the genus Oecomys of family Cricetidae. Its distribution extends over much of Bolivia and into nearby Brazil and Paraguay. Although Oecomys has been recorded from Argentina, it is uncertain whether those records represent O. mamorae. It is found in a variety of habitats at elevations from 200 to 2100 m, where it feeds on fruit and green seeds.
Pseudoryzomys simplex, also known as the Brazilian false rice rat or false oryzomys, is a species of rodent in the family Cricetidae from south-central South America. It is found in lowland palm savanna and thorn scrub habitats. It is a medium-sized species, weighing about 50 grams (1.8 oz), with gray–brown fur, long and narrow hindfeet, and a tail that is about as long as the head and body. The IUCN has assessed its conservation status as being of least concern, although almost nothing is known about its diet or reproduction.
Oligoryzomys is a genus of rodents in the tribe Oryzomyini of family Cricetidae. Many species are known as pygmy rice rats or colilargos. The genus is found from Mexico to Tierra del Fuego and includes approximately 17 species.
Oecomys speciosus, also known as the savannah oecomys, arboreal rice rat, or Venezuelan arboreal rice rat, is a species of rodent in the genus Oecomys of family Cricetidae. It ranges over northeastern Colombia and much of Venezuela, including the island of Trinidad. This rodent lives in tropical rainforest and tropical dry forest, including secondary forest and gallery forest, as well as in savanna habitat.
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.
Oryzomys gorgasi, also known as Gorgas's oryzomys or Gorgas's rice rat, is a rodent in the genus Oryzomys of family Cricetidae. First recorded in 1967, it is known from only a few localities, including a freshwater swamp in the lowlands of northwestern Colombia and a mangrove islet in northwestern Venezuela. It reportedly formerly occurred on the island of Curaçao off northwestern Venezuela; this extinct population has been described as a separate species, Oryzomys curasoae, but does not differ morphologically from mainland populations.
Mindomys hammondi, also known as Hammond's rice rat or Hammond's oryzomys, is an endangered species of rodent in the tribe Oryzomyini of family Cricetidae. Formerly considered to be related with Nectomys, Sigmodontomys, Megalomys, or Oryzomys, it is now placed in then genus Mindomys, but its relationships remain obscure; some evidence supports a placement near Oecomys or as a basal member of Oryzomyini.
Eremoryzomys polius, also known as the gray rice rat or the Marañon oryzomys, is a rodent species in the tribe Oryzomyini of the family Cricetidae. Discovered in 1912 and first described in 1913 by Wilfred Osgood, it was originally placed in Oryzomys and named Oryzomys polius. In 2006, a cladistic analysis found that it was not closely related to Oryzomys in the strict sense or to any other oryzomyine then known, so that it is now placed in its own genus, Eremoryzomys. The Brazilian genus Drymoreomys, named in 2011, is probably the closest relative of Eremoryzomys. Eremoryzomys has a limited distribution in the dry upper valley of the Marañón River in central Peru, but may yet contain more than one species.
Aegialomys xanthaeolus, also known as the yellowish oryzomys or yellowish rice rat, is a species of rodent in the family Cricetidae. It belongs to the genus Aegialomys in tribe Oryzomyini, which was not recognized as distinct from Oryzomys until 2006. It is found in coastal Ecuador and Peru. Though it is currently the only formally recognized mainland species of Aegialomys, at least one other exists. The specific name is sometimes incorrectly spelled "xantheolus", without the second "a".
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.
Euryoryzomys is a genus of rodents in the tribe Oryzomyini of family Cricetidae. It includes seven species, which are distributed in South America. Until 2006, its members were included in the genus Oryzomys, but they are not closely related to the type species of that genus, and therefore they were placed in a new genus. They are most closely related to genera like Hylaeamys and Transandinomys; many members of these genera were previously placed in a single species, known as Oryzomys capito. The genus name, Euryoryzomys, combines the name "Oryzomys" with the Ancient Greek word eurus "broad", referring to the broad range in distribution of the genus.
Oecomys sydandersoni is an arboreal species of rodent in the genus Oecomys. It lives in forest patches in a small area in eastern Bolivia. It is a medium-sized species, weighing about 45 g (1.6 oz), with mostly grayish and brownish fur and short and broad hindfeet with well-developed pads.
In anatomy, posterolateral palatal pits are gaps at the sides of the back of the bony palate, near the last molars. Posterolateral palatal pits are present, in various degrees of development, in several members of the rodent family Cricetidae. Many members of the family lack them or have only simple pits, but Arvicolinae and Oryzomyini have more highly developed posterolateral palatal pits. Posterolateral palatal pits are also present in some other rodents, including Glis, Jaculus, Hystrix, Abrocoma, Ctenomys, Chinchilla, and Lagidium.
Eutrombicula batatas is a species of chigger.
