Chaetophractus vellerosusscreaming hairy armadillo

Geographic Range

C. vellersus is distributed in western Bolivia and in northwestern provinces of Argentina in the Monte Desert (Montgomery, 1985).


The hairy armadillo lives in sloping burrows in desert sand dunes. Chaetophractus avoids summer heat and dessication by being fossorial and nocturnal. In the winter, they are diurnal. Their burrows are insulated against extreme heat because of their depth (Montgomery, 1985).

Physical Description

Armadillos possess a characteristic protective armor that consists of the shield on the head; a small shield between the ears on the back of the neck; and a carapace that protects the shoulders, back, sides, and rump. The carapace has 6 to 8 movable bands. This species has more hair than most armadillos. The hairs project from between the scales of the body armor, and the limbs and belly are covered with whitish or light brown hairs. The male is generally larger than the female, and both sexes are heavier in the winter due to a thick layer of fat under the skin (Montgomery, 1985; Nowak, 1997).

  • Average mass
    840 g
    29.60 oz
  • Average basal metabolic rate
    1.707 W


Breeding takes place in the autumn. The gestation period is 60 to 75 days and there is more than one litter annually. Litters usually consist of two young, often one male and one female. The young weigh 155 grams at birth, open their eyes after 16 to 30 days, are weaned at 50 to 60 days, and reach sexual maturity at 9 months (Nowak, 1997).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual


  • Average lifespan
    Status: captivity
    16.2 years


Chaetophractus vellerosus are solitary species that roams away from their burrow during the night (Montgomery, 1985).

Communication and Perception

Food Habits

Chaetophractus vellerosus is omnivorous, feeding on plant material and on insects. Their main source of insects come from the beetle family (Montgomery, 1985).

Economic Importance for Humans: Positive

Humans frequently eat the hairy armadillo (Montgomery, 1985).

Economic Importance for Humans: Negative

These animals may burrow extensively in loose farm soil and damage crops (Montgomery,1985).

Conservation Status


Other Comments

Chaetophractus vellerosus has the ability to produce highly concentrated urine. This enables it to maintain water balance without drinking for long periods of time, despite the arid nature of its environment. (Montgomery, 1985).


Michelle Porrett (author), University of Michigan-Ann Arbor.



living in the southern part of the New World. In other words, Central and South America.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

scrub forest

scrub forests develop in areas that experience dry seasons.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


uses touch to communicate

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


Nowak, R. M. 1997.

Montgomery, G.G. 1985. Evolution and Ecology of Armadillos, Sloths, and Vermilinguas. Smithsonian Institution Press. Washington and London