Cerradomys
Encyclopedia
Cerradomys is a genus
of oryzomyine
rodent
s from eastern Bolivia
, Paraguay
, and central Brazil
found in cerrado
, Caatinga
and Gran Chaco
habitats. The species in this genus have historically been placed in Oryzomys
, but according to cladistic
research, they are not more closely related to the type species
of Oryzomys than species in some other genera are. Its sister group may be a clade of oryzomyines living in open or aquatic habitats, comprising, among others, Aegialomys
, Nectomys
and Sigmodontomys
. Sooretamys angouya, also formerly in Oryzomys, is another relative; it has been placed in the same group as the species of Cerradomys in the past. The generic name Cerradomys is a compound of the word "Cerrado" and the Ancient Greek mys "mouse" and therefore means "Cerrado mouse".
The dorsal pelage is brownish, the ventral pelage, greyish. It has small ears and a relatively long tail. There are crowns of hair on the hindfeet at the bases of the claws.
In addition to its external classification, the internal classification of the group is also subject to change. Until 2002, all members of the group were placed in a single species, then called Oryzomys subflavus, but since then, seven new species have been described, often on the basis of karyotypic
differences, but two of these later turned out to represent the same species.
The genus currently contains the following species:
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of oryzomyine
Oryzomyini
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of 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...
rodent
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....
s from eastern 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...
, 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...
, and 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...
found in cerrado
Cerrado
The Cerrado, is a vast tropical savanna ecoregion of Brazil, particularly in the states of Gioas and Minas Gerais...
, Caatinga
Caatinga
Caatinga is a type of vegetation, and an ecoregion characterized by this vegetation in the northeastern part of Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation"...
and Gran Chaco
Gran Chaco
The Gran Chaco is a sparsely populated, hot and semi-arid lowland region of the Río de la Plata basin, divided among eastern Bolivia, Paraguay, northern Argentina and a portion of the Brazilian states of Mato Grosso and Mato Grosso do Sul, where it is connected with the Pantanal region...
habitats. The species in this genus have historically been placed in 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...
, but according to cladistic
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
research, they are not more 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 than species in some other genera are. Its sister group may be a clade of oryzomyines living in open or aquatic habitats, comprising, among others, Aegialomys
Aegialomys
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...
, Nectomys
Nectomys
Nectomys is a genus of rodent in the tribe Oryzomyini of family Cricetidae. It is closely related to Amphinectomys and was formerly considered congeneric with Sigmodontomys...
and Sigmodontomys
Sigmodontomys
Sigmodontomys is a genus of rodent in the tribe Oryzomyini of family Cricetidae. It is related to Nectomys and Melanomys and was previously included in Nectomys. It includes two species, Sigmodontomys alfari and the much rarer Sigmodontomys aphrastus, but whether these are indeed each other's...
. Sooretamys angouya, also formerly in Oryzomys, is another relative; it has been placed in the same group as the species of Cerradomys in the past. The generic name Cerradomys is a compound of the word "Cerrado" and the Ancient Greek mys "mouse" and therefore means "Cerrado mouse".
The dorsal pelage is brownish, the ventral pelage, greyish. It has small ears and a relatively long tail. There are crowns of hair on the hindfeet at the bases of the claws.
In addition to its external classification, the internal classification of the group is also subject to change. Until 2002, all members of the group were placed in a single species, then called Oryzomys subflavus, but since then, seven new species have been described, often on the basis of karyotypic
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
differences, but two of these later turned out to represent the same species.
The genus currently contains the following species:
- Cerradomys goytaca
- Cerradomys langguthiCerradomys langguthiCerradomys langguthi is a species of rodent from South America in the genus Cerradomys. It occurs only in northeastern Brazil and was formerly included in C. subflavus.-Literature cited:...
- Cerradomys maracajuensis
- Cerradomys marinhus
- Cerradomys scottiCerradomys scottiCerradomys scotti, also known as Lindbergh's Oryzomys, is a rodent species from South America in the genus Cerradomys. It is terrestrial and is found in the cerrado ecozone of south central Brazil, Bolivia and Paraguay...
(including Oryzomys andersoni) - Cerradomys subflavus
- Cerradomys vivoiCerradomys vivoiCerradomys vivoi is a species of rodent from South America in the genus Cerradomys. It occurs only in eastern Brazil, in the states of Bahia, Goiás, and Sergipe, and was formerly included in C. subflavus.-Literature cited:...