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 n ...
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 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 das ...
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-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 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
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, and northwest
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
. 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 a ...
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. 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 of Africa. Both
morphological and
molecular 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
Further reading
*Kingdon, J. 1997. ''The Kingdon Field Guide to African Mammals''. Academic Press Limited, London.
*McKenna, Malcolm C., and Bell, Susan K. 1997. ''Classification of Mammals Above the Species Level.'' Columbia University Press, New York, 631 pp.
*Nowak, R. M. 1999.'' Walker's
Mammals of the World,'' Vol. 2. Johns Hopkins University Press, London.
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