Pouched rat
Encyclopedia
Pouched rats are a group of Africa
n rodent
s in the subfamily Cricetomyinae. They are members of the family Nesomyidae
, which contains other African muroids
such as climbing mice
, Malagasy mice
, and the white-tailed rat
. All nesomyids are in the superfamily Muroidea
, a large and complex clade
containing 1/4 of all mammal
species
. Sometimes the pouched rats are placed in the family Muridae
along with all other members of the superfamily Muroidea
.
Pouched rats are found throughout much of sub-Saharan Africa with the exception of southern Africa. They are characterized by having large cheek pouches and a distinctive molar
morphology
. The molars are very similar to the type seen in the subfamily Murinae
, but pouched rats probably evolved this similarity through convergent evolution
.
There are three very different genera
of pouched rats. The giant pouched rat
is notable for being the largest of the muroids
. A giant pouched rat was also implicated as a carrier in a small outbreak of monkeypox
in the USA.
The subfamily Cricetomyinae contains three genera and eight species.
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
n 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 in the subfamily Cricetomyinae. They are members of the family Nesomyidae
Nesomyidae
Nesomyidae is a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar...
, which contains other African muroids
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. They occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to...
such as climbing mice
Dendromurinae
Dendromurinae is a subfamily of rodents in the family Nesomyidae and superfamily Muroidea. The dendromurines are currently restricted to Africa, as is the case for all extant members of the family Nesomyidae. The authorship of the subfamily has been contributed to both Alston, 1876, and to G. M...
, Malagasy mice
Nesomyinae
The Malagasy rats and mice are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble gerbils, rats, mice, voles, and even rabbits...
, and the white-tailed rat
White-tailed Rat
The white-tailed rat, Mystromys albicaudatus, also known as the white-tailed mouse, is the only member of the subfamily Mystromyinae in the family Nesomyidae...
. All nesomyids are in the superfamily Muroidea
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. They occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to...
, a large and complex clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
containing 1/4 of all mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
. Sometimes the pouched rats are placed in the family Muridae
Muridae
Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....
along with all other members of the superfamily Muroidea
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. They occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to...
.
Pouched rats are found throughout much of sub-Saharan Africa with the exception of southern Africa. They are characterized by having large cheek pouches and a distinctive molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
. The molars are very similar to the type seen in the subfamily Murinae
Murinae
The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. This subfamily is larger than all mammal families except the Cricetidae and Muridae, and is larger than all mammal orders except the bats and the remainder of the...
, but pouched rats probably evolved this similarity through convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
.
There are three very different genera
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 pouched rats. The giant pouched rat
Giant pouched rat
The giant pouched rats of sub-Saharan Africa are large muroid rodents. Their head and body length ranges from 25–45 cm with scaly tails ranging from 36–46 cm...
is notable for being the largest of the muroids
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. They occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to...
. A giant pouched rat was also implicated as a carrier in a small outbreak of monkeypox
Monkeypox
Monkeypox also known as cockpox is an exotic infectious disease caused by the monkeypox virus. The disease was first identified in laboratory monkeys, hence its name, but in its natural state it seems to infect rodents more often than primates...
in the USA.
The subfamily Cricetomyinae contains three genera and eight species.
Classification
Subfamily Cricetomyinae - Pouched rats- Genus BeamysBeamysBeamys is a genus of rodent in the Nesomyidae family.It contains the following species:* Lesser Hamster-rat * Greater Hamster-rat -References:...
- Lesser Hamster-ratLesser Hamster-RatThe Lesser Hamster-rat or Long-tailed Pouched Rat is a species of rodent in the Nesomyidae family.It is found in Kenya and Tanzania.Its natural habitat is subtropical or tropical moist lowland forests....
, Beamys hindei - Greater Hamster-ratGreater Hamster-RatThe Greater Hamster-rat, Greater Long-tailed Pouched Rat, or Long-tailed Pouched Rat is a species of rodent in the Nesomyidae family.It is found in Malawi, Tanzania, and Zambia....
, Beamys major
- Lesser Hamster-rat
- Genus Cricetomys - Giant pouched rats
- Southern Giant Pouched RatSouthern Giant Pouched RatThe Southern Giant Pouched Rat is a species of rodent in the Nesomyidae family. It is distributed throughout southern Africa, notably Zimbabwe, Kenya, Tanzania, Zambia, and the Democratic Republic of Congo.-Synonyms:...
, Cricetomys ansorgei - Gambian Pouched RatGambian pouched ratThe Gambian pouched rat , also known as the African giant pouched rat, is a nocturnal pouched rat of the giant pouched rat genus Cricetomys. It is among the largest muroids in the world, growing up to about long including their tail which makes up half their length...
, Cricetomys gambianus - Emin's Pouched Rat, Cricetomys emini
- Kivu Giant Pouched RatKivu Giant Pouched RatThe Kivu Giant Pouched Rat, is a species of rodent in the Nesomyidae family. It has a distribution in Southern Africa.-Further reading:*...
, Cricetomys kivuensis
- Southern Giant Pouched Rat
- Genus SaccostomusSaccostomusSaccostomus is a genus of rodent in the Nesomyidae family.It contains the following species:* South African Pouched Mouse * Mearns's Pouched Mouse -References:...
- Pouched mice- South African Pouched MouseSouth African Pouched MouseThe South African Pouched Mouse or Southern African Pouched Mouse is a species of rodent in the family Nesomyidae, which is viewed as actually representing a complex of undescribed species...
, Saccostomus campestris - Mearns's Pouched MouseMearns's Pouched MouseMearns's Pouched Mouse is a species of rodent in the Nesomyidae family.It is found in Ethiopia, Kenya, Somalia, Tanzania, and Uganda....
, Saccostomus mearnsi
- South African Pouched Mouse