Priodontes maximusgiant armadillo

Geographic Range

Giant armadillos, Priodontes maximus, range through much of the neotropics. They are found from southeastern Venezuela and the Guianas in the north through northeastern Brazil, Paraguay, and the extreme north of Argentina. Most of this species' range lies within the Amazon basin. (Eisenberg and Redford, 1999; Parera, 2002)


Priodontes maximus is typically found in a diverse range of habitats, usually in areas with a large termite population. Although rare, they have been sighted in tropical and subtropical rainforest, savanna, Brazilian floodplains, and arid and semiarid woodlands. In these areas, the armadillos have been found residing up to 500 meters above sea level. (Emmons, 1997; Parera, 2002; Emmons, 1997; Parera, 2002)

  • Range elevation
    0 to 500 m
    0.00 to 1640.42 ft

Physical Description

Priodontes maximus is easily distinguished from other armadillos due to its enormous size. In most cases, it weighs upwards of 26 kg, and measures between 832 and 960 mm. Another recognizable characteristic is its enlarged central claw, much like that of giant anteaters, Myrmecophaga tridactyla. Typical of armadillos, Priodontes maximus has a carapace covered with bony scales. The dorsal portion of this carapace appears black/gray, while the ventral portions of the carapace are much lighter and separated by a noticeable band. Underneath the carapace, the naked body appears wrinkly and pinkish. The legs and tail are covered with tough pentagonal scales. The head is conical, with a blunt rostrum. (Eisenberg and Redford, 1999; Emmons, 1997)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    18.7 to 32.3 kg
    41.19 to 71.15 lb
  • Average mass
    26.8 kg
    59.03 lb
  • Range length
    832 to 960 mm
    32.76 to 37.80 in
  • Average length
    895.5 mm
    35.26 in
  • Average basal metabolic rate
    16.892 W


Very little information is available on the mating habits of South American armadillos. No accounts of the mating system of P. maximus have been published as yet. Considering the habits of other armadillos, however, one may infer that two giant armadillos pair for each breeding season while sharing a burrow. (McBee and Baker, 1982)

Very little is known about the reproductive behavior of giant armadillos. They typically give birth to a single offspring (occasionally two), which weigh up to 113 g at birth, and already possess tough skin. Weaning begins about 4 to 6 weeks after birth, and after weaning, the young become independent. Armadillos reach sexual maturity within 9 to 12 months of birth. (Nowak, 1999; Nowak, 1999; Parera, 2002)

  • Breeding interval
    The breeding interval of these animals is not known.
  • Breeding season
    It is not known whether these animals breed seasonally.
  • Range number of offspring
    1 to 2
  • Average number of offspring
  • Average number of offspring
  • Average gestation period
    4 months
  • Average gestation period
    122 days
  • Range weaning age
    4 to 5 months
  • Average weaning age
    6 months
  • Range time to independence
    4 to 6 months
  • Range age at sexual or reproductive maturity (female)
    9 to 12 months
  • Range age at sexual or reproductive maturity (male)
    9 to 12 months

Little is known about parental care in giant armadillos. Mothers stay with the young and nurse them for 4 to 6 weeks. Afterwards, the young stay with the mother until they reach independence at around 6 months of age. The role of the male in parental care has not been documented for P. maximus. (Nowak, 1999; Parera, 2002)

  • Parental Investment
  • no parental involvement
  • female parental care
  • pre-fertilization
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female


The lifespan of these animals can reach 12 to 15 years. (Nowak, 1999)


Priodontes maximus is largely nocturnal and terrestrial. These armadillos forage alone, only assosciating with others to mate. They dig large burrows in which they rest, using their spade-like third claws. These animals are capable of balancing on their hind legs and tail, allowign them to reach high into termite mounds (this technique also comes in handy for warding off predators). Once a mound has been eradicated, an armadillo will bury itself beneath the remains of the mound and reside there for a period up to 24 hours before moving on. It has been said that P. maximus is also a good swimmer. (Emmons, 1997; Nowak, 1999; Parera, 2002)

  • Range territory size
    3 (high) km^2

Home Range

The home range of P. maximus spans 450 hectares minimum, with a maximum of 3 square kilometers. (Parera, 2002)

Communication and Perception

No information exists suggesting any sort of communication between animals. The strongest sense possessed by armadillos is olfaction, which could support a case for the presence of an olfactory communication channel between individuals. However, this is merely speculation and has yet to be tested.

Tactile communication undoubtedly occurs between a mother and her offspring, as well as between mates. (McBee and Baker, 1982)

Food Habits

Giant armadillos have a very specialized diet consisting of termites and certain ant species. These animals roam throughout their range in search of termite mounds in which to burrow. Once they have found a mount, they completely eradicate it. This species has also been documented eating carrion, worms, and other small vertebrates. (Emmons, 1997; Nowak, 1999; Parera, 2002)

  • Animal Foods
  • reptiles
  • carrion
  • insects
  • terrestrial worms


Due to the large size and heavy shielding of these animals, giant armadillos have few natural predators. Unlike other armadillos, P. maximus cannot completely hide itself within its carapace. They occasionally fall prey to jaguars (Panthera onca), and pumas (Puma concolor). Humans, however, have had the deadliest impact on the species. (Nowak, 1999; Parera, 2002)

  • Known Predators

Ecosystem Roles

The most notable ecosystem role played by P. maximus is its control over the termite and ant populations in a small region. By keeping these huge populations in check, the ecosystem can maintain a state of equilibrium, making P. maximus somewhat of a keystone species. Also, due to its fossorial nature, this species aids in soil aeration. (Emmons, 1997; Nowak, 1999; Parera, 2002)

Economic Importance for Humans: Positive

At one point, before their numbers dwindled, giant armadillos were key in controlling leafcutter ant populations, which could reach enormous sizes and destroy crops. These animals have also been hunted by natives for their meat. (Emmons, 1997)

  • Positive Impacts
  • food
  • controls pest population

Economic Importance for Humans: Negative

Although giant armadillos can be damaging to crops while digging through soil in search of animal prey, they never directly consume plants. (Emmons, 1997; Parera, 2002)

  • Negative Impacts
  • crop pest

Conservation Status

Priodontes maximus is a victim of habitat infringement and overhunting. Many native farmers kill the armadillo on sight because they are thought to damage crops. (Emmons, 1997; Nowak, 1999; Parera, 2002)


Nancy Shefferly (editor), Animal Diversity Web.

David Armitage (author), Animal Diversity Web, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.



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

World Map


uses sound to communicate


living in landscapes dominated by human agriculture.

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.


an animal that mainly eats meat


flesh of dead animals.


uses smells or other chemicals to communicate


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.

female parental care

parental care is carried out by females


union of egg and spermatozoan


A substance that provides both nutrients and energy to a living thing.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


Referring to a burrowing life-style or behavior, specialized for digging or burrowing.


An animal that eats mainly insects or spiders.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

keystone species

a species whose presence or absence strongly affects populations of other species in that area such that the extirpation of the keystone species in an area will result in the ultimate extirpation of many more species in that area (Example: sea otter).


Having one mate at a time.


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.


active during the night


generally wanders from place to place, usually within a well-defined range.


rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

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

soil aeration

digs and breaks up soil so air and water can get in


lives alone


uses touch to communicate


Living on the ground.


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

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.


uses sight to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


Eisenberg, J., K. Redford. 1999. Mammals of the Neotropics: The Central Neotripics. Vol. 3: Ecuador, Peru, Bolivia, Brazil. Chicago & London: University of Chicago Press.

Emmons, L. 1997. Neotropical Rainforest Mammals. Chicago: University of Chicago Press.

Husson, A. 1978. The Mammals of Suriname. Leiden, The Netherlands: E.J. Brill.

Linares, O. 1998. Mamiferos de Venezuela. Caracas: Sociedad Conservacionista Audobon De Venezuela.

McBee, K., R. Baker. 1982. Dasypus novemcinctus. Mammalian Species, 162: 1-9. Accessed March 09, 2004 at

Nowak, R. 1999. Walker’s Mammals of the World, Sixth Edition.. Baltimore and London: The Johns Hopkins University Press.

Parera, A. 2002. Los mamiferos de la Argentina y la region austral de Sudamerica. Buenos Aires: El Ateneo.