Armadillos are members of Xenarthra, which also includes the vermilinguas (ant and termite eaters) and sloths. Osteological characteristics of Xenarthra include xenarthrous articulations of the vertebrae, the fusion of the transverse processes of the anterior caudal vertebrate to the ischia to form a single pelvic assembly, and the presence of dermal ossicles (Engelmann, 1985).

Zaedyus pichiy, the pichi, is the only species allocated to the genus Zaedyus. The pichi has been allied with both Chaetophractus and Euphractus. Although more similar externally with Euphractus, karyological evidence suggests that it is more closely related to Chaetophractus (Nowak, 1999).

The range of Z. pichiy extends through central and southern Argentina, the Andean grasslands of Chile to the Strait of Magellan. Externally, Z. pichiy is characterized by a dark brown head shield and carapace, thickly set dorsal plates, distally separate digits with well-developed claws, and small ears (Nowak, 1999). Osteological characteristics include no teeth on the premaxilla (possessing only 8 maxillary and 9 mandibular pairs), a proportionally greater height of the jugal, and the nuchal scutes are shortest in anteroposterior length (Wetzel, 1985). They are typically solitary and live in small burrows. The diet of the pichi consists primarily of insects, worms, and other small animals (Nowak, 1999).

Imagery of the entire body of Zaedyus pichiy is also available.

This specimen was collected from Mecheiquil dept Malarque, Mendoza Province, Argentina on the 23 March 1970 by R. D. Sage. It was made available to The University of Texas High-Resolution X-ray CT Facility for scanning courtesy of the Texas Memorial Museum Vertebrate Paleontology Laboratory. Funding for scanning was provided by an National Science Foundation Digital Libraries Initiative grant to Dr. Timothy Rowe of The University of Texas at Austin.

This upper body of this specimen was scanned by Matthew Colbert on 21 January 2004 along the coronal axis for a total of 999 slices. Each slice is 0.1 mm thick, with an interslice spacing of 0.1 mm and a field of reconstruction of 88 mm. This specimen of Zaedyus pichiy is dessicated; therefore, the soft tissue and bone are similar in grayscale values.

Literature

Codón, S. M., and E. B. Casanave. 2000. Comparative morphology of the ovaries of three species of Dasypodidae (Mammalia, Xenarthra). Revista chilena de anatomía 18:251-257.

Engelmann, G. F. 1985. The phylogeny of the Xenarthra; pp. 51-64 in G. G. Montgomery (ed.), The Evolution and Ecology of Armadillos, Sloths, and Vermilinguas. Smithsonian Institution Press, Washington D. C.

Galíndez, E. J., S. Estecondo, and E. B. Casanave. 2003. The spleen of Zaedyus pichiy (Mammalia, Dasypodidae): a light and electron microsopic study. Anatomia, Histologia, Embryologia: Journal of Veterinary Medecine, Series C, 32:194-199.

Montgomery, G. G. (ed.). 1985. The Evolution and Ecology of Armadillos, Sloths, and Vermilinguas. Smithsonian Institution Press, Washington, D. C., 451 pp.

Nowak, R. M. 1999. Walker's Mammals of the World, Volume I. Johns Hopkins University Press, Baltimore, Maryland, 836 pp.

Talmage, R. V. N., and G. D. Buchanan. 1954. The armadillo (Dasypus novemcinctus): a review of its natural history, ecology, anatomy and reproductive physiology. Rice University Monograph in Biology, Rice University Studies 41:1-135.

Wetzel, R. M. 1985. Taxonomy and distribution of armadillos, Dasypodidae; pp. 23-46 in G. G. Montgomery (ed.), The Evolution and Ecology of Armadillos, Sloths, and Vermilinguas. Smithsonian Institution Press, Washington D. C.

Links

Species account and images of the skull of Zaedyus pichiy on the Animal Diversity Web (Univ. of Michigan Museum of Zoology).

Information and images of Z. pichiy on Armadillo Online.

None available.