The dassie rat (''Petromus typicus'') is an African

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

found among rocky outcroppings. It is the only living member of its genus, '' Petromus'', and family, '' Petromuridae''. The name " dassie" means " hyrax" in

Afrikaans Afrikaans is a West Germanic languages, West Germanic language spoken in South Africa, Namibia and to a lesser extent Botswana, Zambia, Zimbabwe and also Argentina where there is a group in Sarmiento, Chubut, Sarmiento that speaks the Pat ...

,dassie rats are not to be confused with Cape hyraxes, which are also called dassies and are not rodents. and the two animals are found in similar habitats. ''Petromus'' means "rock mouse" and dassie rats are one of many rodents sometimes called rock rats. The family and genus names are sometimes misspelled as Petromyidae and ''Petromys''.

Characteristics

Dassie rats are

squirrel Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrel ...

-like in appearance. Their tails are hairy, but not bushy whereas the soles of their feet are distinctly bare and have pads. Their heads are noticeably flattened. The overall coloration can be a range of browns, greys, or almost black. The nose is yellowish and tends to stand out. They have no underfur. The

teat A teat is the projection from the mammary glands of mammals from which milk flows or is ejected for the purpose of feeding young. In many mammals, the teat projects from the udder. The number of teats varies by mammalian species and often corr ...

s are located on the sides of the torso, which allows the young to feed from the side when crammed in a narrow rock crevice.

Natural history

Dassie rats are restricted to rocky outcrops in

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

, parts of

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

, and northwest

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. They are famous for being able to squeeze into extremely narrow crevices. This is accomplished due to their flattened skulls and flexible ribs. Dassie rats feed primarily on

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

es, but will sometimes eat

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

s, seeds, and

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

. They have high crowned and rooted cheek teeth. Females give birth to a pair of offspring just once a year, an unusually slow reproductive rate among rodents.

Relatives

Dassie rats are the only remaining members of a once-diverse family that first appeared in the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

of Africa. Both morphological and

molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

studies suggest the closest living relatives to the dassie rats are the African

cane rat The genus ''Thryonomys'', also known as the cane rats or grasscutters, is a genus of rodent found throughout Sub-Saharan Africa, the only extant members of the family '' Thryonomyidae''. They are eaten in some African countries and are a pest sp ...

s in the family Thryonomyidae. These two families, along with related fossil families such as † Phiomyidae, represented an important early radiation of rodents in Africa.

References

External links

Animal Diversity Web site about dassie ratsThe Dassie Rat, Focusing On WildlifeThe Dassie Rat – a rodent that chews the cud
{{Taxonbar, from=Q838740 Petromuridae Rodents of Africa Mammals described in 1831 Extant Pleistocene first appearances Taxa named by Andrew Smith (zoologist) Mammals of Namibia Mammals of Angola Mammals of South Africa

Characteristics

Natural history

Relatives

References

Further reading

External links