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

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

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

dassie Hyraxes (), also called dassies, are small, thickset, herbivorous mammals in the Order (biology), order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between long and weigh between . They are sup ...

" means "

hyrax Hyraxes (), also called dassies, are small, thickset, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between long and weigh between . They are superficially simil ...

" in

Afrikaans Afrikaans (, ) is a West Germanic language that evolved in the Dutch Cape Colony from the Dutch vernacular of Holland proper (i.e., the Hollandic dialect) used by Dutch, French, and German settlers and their enslaved people. Afrikaans gra ...

,dassie rats are not to be confused with

Cape hyrax The rock hyrax (; ''Procavia capensis''), also called dassie, Cape hyrax, rock rabbit, and (in the King James Bible) coney, is a medium-sized terrestrial mammal native to Africa and the Middle East. Commonly referred to in South Africa as the da ...

es, 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-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...

-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 corre ...

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 in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

, parts of

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

, and northwest

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. 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 () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

es, but will sometimes eat

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

s, seeds, and

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

. 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 of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

of Africa. Both morphological and

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

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 Africa south of the Sahara, the only members of the family Thryonomyidae. They are eaten in some African countries and are a pest species ...

s in the family Thryonomyidae. These two families, along with related fossil families such as †

Phiomyidae The Phiomyidae are a family of prehistoric rodents from Africa and Eurasia. A 2011 study placed ''Gaudeamus'' in a new family, Gaudeamuridae. Genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of livin ...

, 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 Hystricognath rodents Rodents of Africa Mammals described in 1831 Extant Pleistocene first appearances

Characteristics

Natural history

Relatives

References

Further reading

External links