Euryoryzomys emmonsae, also known as Emmons' rice rat or Emmons' oryzomys, is a rodent from the Amazon rainforest of Brazil in the genus Euryoryzomys of the family Cricetidae. Initially misidentified as E. macconnelli or E. nitidus, it was formally described in 1998. A rainforest species, it may be scansorial, climbing but also spending time on the ground. It lives only in a limited area south of the Amazon River in the state of Pará, a distribution that is apparently unique among the muroid rodents of the region.
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.
Nephelomys auriventer, also known as the golden-bellied oryzomys or Ecuadorian rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. Oldfield Thomas originally described it, in 1899, as a species of Oryzomys, Oryzomys auriventer, and considered it most similar to Oryzomys aureus. In 1926, a subspecies was described from an Ecuadorian locality, Oryzomys auriventer nimbosus, and it was suggested that O. auriventer was closely related to O. albigularis. This proposal was formalized in 1961 by including O. auriventer within the species O. albigularis, but by 1976 O. auriventer was recognized again as a separate species. In 2006, Oryzomys albigularis and related species, including O. auriventer, were transferred to the new genus Nephelomys. Simultaneously, the former subspecies nimbosus was recognized as a separate species, Nephelomys nimbosus.
Nephelomys devius, also known as the Talamancan oryzomys, Boquete rice rat, Chiriqui rice rat, or montane rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. It is found in cloud forest in the highlands of Costa Rica and western Panama.
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.
Nephelomys keaysi, also known as Keays's oryzomys or Keays's rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. It is found from southeastern Peru to northern Bolivia on the eastern slope of the Andes in Yungas humid forest at altitudes of 1000 to 2600 m. Although its continued existence is not in serious danger and it is listed as "least concern", destruction of its habitat may pose a threat to some populations.
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.
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.
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.
Nephelomys caracolus, also known as the Costa Central oryzomys or caracol rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. It is found in cloud forest in the Cordillera de la Costa Central of Aragua, Miranda, and the Distrito Federal in north-central Venezuela at elevations from 1000 to 2500 m. It is nocturnal and terrestrial, and has a varied diet. In most Nephelomys species, the posterolateral palatal pits, perforations of the palate near the third molar, are conspicuous and receded into a fossa, but in N. caracolus and the Ecuadorian species N. nimbosus, the pits are much smaller.
Nephelomys meridensis, also known as the Mérida oryzomys, is a species of rodent in the genus Nephelomys of family Cricetidae. It is found in cloud forest in the Sierra Nevada de Mérida of western Venezuela at elevations from 1100 to 4000 m. It is solitary, nocturnal and terrestrial, and has a varied diet.
Transandinomys is a genus of rodents in the tribe Oryzomyini of family Cricetidae. It includes two species—T. bolivaris and T. talamancae—found in forests from Honduras in Central America south and east to southwestern Ecuador and northwestern Venezuela in northern South America. Until 2006, its members were included in the genus Oryzomys, but phylogenetic analysis showed that they are not closely related to the type species of that genus, and they have therefore been placed in a new genus. They may be most closely related to genera like Hylaeamys and Euryoryzomys, which contain very similar species. Both species of Transandinomys have had eventful taxonomic histories.
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica. Its generic name is derived from the Ancient Greek word nephelê "mist", referring to the cloud forest habitat of the members of the genus.
Nephelomys childi is a species of rodent in the genus Nephelomys of family Cricetidae. The type locality is at Bogotá, Colombia, and the type locality of its junior synonym, oconnelli, is at a place known as Buenavista, about 50 miles (80 km) southeast of Bogotá. It was named after Mr. George D. Child, who assisted in obtaining the type series.
Nephelomys nimbosus is a species of rodent in the genus Nephelomys of family Cricetidae. Its type locality is at San Antonio on the northeastern slope of the Tungurahua in the Andes of Ecuador, at an altitude of about 6,700 feet (2,000 m). The type series included five individuals.
Nephelomys pirrensis, also known as the Mount Pirre rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. Its type locality is at Mount Pirri or Pirre in eastern Panama, at an altitude of 4,500 feet (1,400 m), and it has also been recorded on Mount Tacarcuna.
Nephelomys pectoralis is a species of rodent in the genus Nephelomys of family Cricetidae. Its type locality is 40 miles (64 km) west of the city of Popayán, Cauca Department, Colombia, at an altitude of 10,340 feet (3,150 m). American zoologist Joel Asaph Allen first described it in 1912 on the basis of 112 specimens from several locations in the Cordillera Occidental. He classified it as a species of Oryzomys, Oryzomys pectoralis, but later subsumed into the species Oryzomys albigularis. When that species was transferred to the new genus Nephelomys in 2006, N. pectoralis was recognized as a separate species.
In rodent anatomy, the zygomatic plate is a bony plate derived from the flattened front part of the zygomatic arch (cheekbone). At the back, it connects to the front (maxillary) root of the zygomatic arch, and at the top it is connected to the rest of the skull via the antorbital bridge. It is part of the maxillary bone, or upper jaw, which also contains the upper cheekteeth. Primitively, rodents have a nearly horizontal zygomatic plate. In association with specializations in zygomasseteric system, several distinct morphologies have developed across the order.
Oryzomys albiventer is a rodent in the genus Oryzomys of family Cricetidae from interior western Mexico, in the states of Jalisco, Guanajuato, and Michoacán. First described in 1901 as a separate species, it was later lumped under O. couesi and the marsh rice rat (O. palustris) until it was reinstated as a species in 2009. It differs from neighboring Oryzomys populations in size and measurements and is a large, brightly colored species with a long tail and robust skull and molars. Its range has been much impacted by agricultural development, but isolated populations are thought to persist.
