This specimen was scanned in two passes. These datasets were not able to be realigned; therefore, the coronal slices for the upper and lower body are given in two separate movies. There is a small amount of overlap between the animations.
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). |
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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).
This entire specimen was scanned by Matthew Colbert on 21 January 2004 along the coronal axis for a total of 1257 slices. The specimen was scanned in three passes, first with base, second without, and third physically flipped. All the slices from the second scan were adjusted by Rachel Racicot to align with the slices from the first pass. The third scan was not integrated because of the large amount of offset. Each slice is 0.2 mm thick, with an interslice spacing of 0.2 mm and a field of reconstruction of 90 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.
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