Osteology and radiology of the thoracic limb of nine-banded armadillo, dasypus novemcinctus linnaeus, 1758

Abstract

In Brazil, injured nine-banded armadillos are frequently taken to wildlife rehabilitation centers due to direct or indirect anthropic interactions, however, database about osseous structures useful to radiographic interpretation are limited. This work provides bones description from thoracic limb of Dasypus novemcinctus as well as references to radiographic interpretation and the best positioning to perform the radiographies. Twelve deceased specimens seized by IBAMA (Brazilian Institute of the Environment and Renewable Natural Resources) were used to check osteology and radiographic anatomy. Radiographic images were taken in practical routine plans of small animals and were followed by limbs dissection and bones preparations. The bone structure of the thoracic limb was similar to those of other species of armadillos. The scapula presented a prominent caudal angle, as well as a thick acromion with a wide hamate process; the humerus is short, spiraled with a prominent deltoid tuberosity and a wide lateral epicondylar crest; the radius and ulna did not present any fusion between then, allowing a wide rotation movement of the forearm. In general, the bone components of the hand maintained a short and robust shape, digits with developed distal phalange followed by long claws. Several sesamoid bones were found in the metacarpal and interphalangical joints. Clear visualization of bone characteristics was possible using proposed positioning to take the radiographies.