Azara's Broad-headed Rice Rat
Encyclopedia
Hylaeamys megacephalus, also known as Azara's Broad-headed Oryzomys or the Large-headed Rice Rat, is a species of rodent
in the genus Hylaeamys
of family Cricetidae
, of which it is the type species
. It is found mainly in lowland tropical rainforest
from its type locality in Paraguay
north through central Brazil
, French Guiana
, Guyana
, Suriname
, and Venezuela
onto Trinidad and Tobago
. To its west and east, other closely related species of Hylaeamys are found: H. perenensis in western Amazonia
, H. acritus
in Bolivia
, and H. laticeps
and H. oniscus
in the Atlantic Forest of eastern Brazil.
It was first described by Spanish
naturalist
Félix de Azara
. Based on his description, several names were given to the animal, including Mus megacephalus Fischer, 1814 and Mus capito Olfers, 1818, both of which were largely forgotten for over a century. When capito was rediscovered in 1960, it came in use (as Oryzomys capito) for a "species" that included about all species now placed in Euryoryzomys
, Hylaeamys
and Transandinomys
. Later, its scope was restricted, most definitively in a detailed study in 1998 by Guy Musser
and coworkers, who also reinstated the older name Mus megacephalus (as Oryzomys megacephalus). In subsequent years, the western Amazonian H. perenensis was reinstated as a species and both were moved to the new genus Hylaeamys, because they are not closely related to the type species
of Oryzomys
.
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the genus Hylaeamys
Hylaeamys
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...
of family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
, of which it is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
. It is found mainly in lowland tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
from its type locality in Paraguay
Paraguay
Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
north through central Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
, Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
, Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...
, and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
onto Trinidad and Tobago
Trinidad and Tobago
Trinidad and Tobago officially the Republic of Trinidad and Tobago is an archipelagic state in the southern Caribbean, lying just off the coast of northeastern Venezuela and south of Grenada in the Lesser Antilles...
. To its west and east, other closely related species of Hylaeamys are found: H. perenensis in western Amazonia
Amazon Rainforest
The Amazon Rainforest , also known in English as Amazonia or the Amazon Jungle, is a moist broadleaf forest that covers most of the Amazon Basin of South America...
, H. acritus
Hylaeamys acritus
Hylaeamys acritus, formerly Oryzomys acritus, is an oryzomyine rodent of the family Cricetidae. It is known only from northeastern Bolivia. It is terrestrial and is found in moist lowland semideciduous forest and savanna.-References:...
in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, and H. laticeps
Hylaeamys laticeps
Hylaeamys laticeps, also known as the Atlantic Forest Oryzomys or Large-headed Rice Rat, is a species of rodent in the genus Hylaeamys of family Cricetidae. It occurs in the Atlantic Forest region of southeastern Brazil...
and H. oniscus
Hylaeamys oniscus
Hylaeamys oniscus, also known as the Sowbug Rice Rat, is a rodent species in the genus Hylaeamys of family Cricetidae. It was formerly placed in the genus Oryzomys as Oryzomys oniscus. It occurs only in northeastern Brazil...
in the Atlantic Forest of eastern Brazil.
It was first described by Spanish
Spanish people
The Spanish are citizens of the Kingdom of Spain. Within Spain, there are also a number of vigorous nationalisms and regionalisms, reflecting the country's complex history....
naturalist
Natural history
Natural history is the scientific research of plants or animals, leaning more towards observational rather than experimental methods of study, and encompasses more research published in magazines than in academic journals. Grouped among the natural sciences, natural history is the systematic study...
Félix de Azara
Félix de Azara
Félix Manuel de Azara was a Spanish military officer, naturalist and engineer. He was born in Barbunales, Aragon....
. Based on his description, several names were given to the animal, including Mus megacephalus Fischer, 1814 and Mus capito Olfers, 1818, both of which were largely forgotten for over a century. When capito was rediscovered in 1960, it came in use (as Oryzomys capito) for a "species" that included about all species now placed in Euryoryzomys
Euryoryzomys
Euryoryzomys is a genus of rodents in the tribe Oryzomyini of family Cricetidae. It includes six 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...
, Hylaeamys
Hylaeamys
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...
and Transandinomys
Transandinomys
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...
. Later, its scope was restricted, most definitively in a detailed study in 1998 by Guy Musser
Guy Musser
Guy Graham Musser is an American zoologist. His main research field is the subfamily Murinae, in which he has described many new species.Musser was born in Salt Lake City, Utah...
and coworkers, who also reinstated the older name Mus megacephalus (as Oryzomys megacephalus). In subsequent years, the western Amazonian H. perenensis was reinstated as a species and both were moved to the new genus Hylaeamys, because they are not closely related to the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of Oryzomys
Oryzomys
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 of the United States and O. couesi of Mexico and Central America—are widespread; the six others have...
.
Literature cited
- Musser, G.G., Carleton, M.D., Brothers, E.M. & Gardner, A.L. 1998b. Systematic studies of oryzomyine rodents (Muridae: Sigmodontinae): diagnoses and distributions of species formerly assigned to Oryzomys "capito". Bulletin of the American Museum of Natural History 236:1-376.
- Musser, G. G. and M. D. Carleton. 2005. Superfamily Muroidea. pp. 894–1531 in Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. | issn = 0003-0082| doi=10.1206/0003-0082(2006)3537[1:TNGOOR]2.0.CO;2}}