Cabassous Chacoensis - Chacoan Naked-tailed Armadillo
Physical Description:
Cabassous chacoensis is one of the smallest
species of the Dasypodidae family. It
has very small eyes and it is distinguished by its ears, which are very small
and funnel-shaped. The ears are widely
separated with a fleshy extension at the anterior margin (Redford and Eisenberg
1992). The armadillo is equipped with
five sharp claws on the forefeet, with the third being the longest (MacDonald
1984). This sickle-shaped claw aids in
feeding and digging (Redford and Eisenberg 1992). The head of Cabassous chacoensis is short and broad (Nowak 1999). Wetzel (1980) recorded the ranges of 4 body measurements:
total length, 300-306 mm; tail length, 90-96 mm; hind foot length, 61 mm; and
ear length, 14-15 mm. The weight is
unspecified (Nixon 1995). The tail of the
armadillo is slender and shorter than the body.
Few armored plates are present on the tail; those that are present are
small, thin, and widely separated (Redford and Eisenberg 1989). This lack of complete armor makes Cabassous chacoensis a unique species.
The dorsal plates are arranged in traverse rows the entire length of the
body (Redford and Eisenberg 1989). The
carapace of the armadillo is dark brown to black with yellowish edges. The under parts are yellow-gray (Nixon 1995). There are 10-13 moveable bands across the
back (Nowak 1999). Cabassous chacoensis has no teeth on the premaxilla bone. The
actual number of teeth varies from 7/8 to 10/9 on the upper and lower jaw
respectively (Redford and Eisenberg 1989). Cabassous chacoensis walks
on the claws on its forefeet and the soles of its hind feet (Nixon 1995). They do not usually move swiftly, but can run
quickly for short distances if pursued (Nixon 1995, MacDonald 1984). To escape predators or potential danger the
armadillos usually burrow or go to
water (Nixon 1995).
Distribution:
Cabassous chacoensis is confined to the xeric
Chaco of Argentina and Paraguay
as well as the gran Chaco of
northwest Argentina,
western Paraguay,
southeast Bolivia
and the adjacent part of Brazil
(Redford and Eisenberg 1989).
Ontogeny and
Reproduction:
Young are born singly. The adults are considered solitary (Redford
and Eisenberg 1992).
Ecology and Behavior:
Cabassous chacoensis lives in a variety of habitat
including grasslands, semi-arid and moist lowlands, and uplands. It prefers moist habitats with well-drained
soil (Wetzel 1980). They are a fossorial
species, digging burrows in open ground and on river embankments (Nixon
1995). Cabassous chacoensis generally feeds on ants and
termites, which they locate by the smell of leaf litter and soil. The long middle claw on the forefoot is used
to cut small roots and to dig for food in rotting or dead roots. The long tongue is used to extract insects
from their tunnels (Nixon 1995). Cabassous chacoensis is nocturnal.
Remarks:
Cabassous chacoensis can be mistaken for Cabassous unicinctus
(Wetzel 1982). When handled, the males
make a loud grunt while the females remain silent (Wetzel 1982). Little is known of the armadillo and its
natural history. Only four individuals
have been found and documented worldwide (Redford and Eisenberg 1989). The Museum of Natural History in Paraguay has
only one individual in its collection (Martinez 1996).
Literature Cited:
Macdonald, D. 1984. Encyclopedia of Mammals. Andromedia
Oxford
University. Pp. 781-783.
Martinez, O. R. 1996. Colecciones de Flora y Fauna del Mureo
Nacional de Historia Natural del Paraguay.
San Lorezo, Paraguay. Pg 481.
Nixon, J. 1995.
Minnesota
State
University
website. http://www.msu.edu/~nixonjos/armadillo/cabassous.html Accessed 13 November, 2004.
Nowak, R. M. 1999. Walker’s Mammals of the World, 6th
Edition, Volume 2. John Hopkins
University Press, Baltimore. Pp. 162-163.
Redford, K. H.
and J. F. Eisenberg. 1989. Mammals of the Neotropics,
Volume 1.University of Chicago
Press, Chicago. Pg 99.
____________________________. 1992.
Mammals of the Neotropics, Volume 2. University
of Chicago Press, Chicago. Pp. 52-54.
Wetzel, R. M. 1980. Revision of the naked-tailed armadillos,
genus Cabassous. Ann
Carnegie
Museum 49:678-84.
___________. 1982a. Systematics,
distribution, ecology, and conservation of South American edentates. In
Mammalian
Biology in South America, (eds) M. Mares and H. Genoways. Pittsburgh,
University of
Pittsburgh,
Special Publication Series Pymatuning Laboratory of Ecology. Pp 345-375.
___________. 1982b. Mammals of Chaco
of Paraguay. Nat. Geog. Sos. Res. Repts.
14: 679-84.
Reference written by Shannon
Murray, Biol 378 (Mammalogy),
University of Wisconsin – Stevens
Point: Edited by Chris Yahnke. Page last updated July
25, 2005.
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