Morphology of laryngeal cartilage of the nine-banded armadillo (Dasypus novemcinctus) Linnaeus, 1758.

Armadillos, Xenarthras representatives, known for adaptability to different ecosystems, own specific morphophysiological characteristics that are not known and deserve to be studied. The aim of this study was to describe the morphology of cartilage of the larynx of the nine-banded armadillo (Dasypus novemcinctus). Five dead armadillos were donated by the Chico Mendes Institute of Biodiversity (ICMBio-PI) to the Federal University of Piauí. The animals were fixed and dissected for removal of the larynx. The cartilages were identified and described, photodocumented, and schematized. Fragments with about 0.5 cm of each cartilage were collected and submitted to classical histology for Hematoxylin-Eosin coloring. The slides were assembled in enterlan and analyzed under a light microscope. The larynx of the armadillo (D. novemcinctus) is located in the mentonian region, ventral to the esophagus, and due to the total positioning of the tongue in the oral cavity, there is also a cranial cervical position in this species. The larynx has five cartilages, they are: a cricoid, a thyroid, an epiglottis, and two arytenoids. The corniculate process is present; however, the cuneiform process is absent. The epiglottis has a discrete bifurcation at its apex. In all cartilages epithelial variations are observed. The tissues are varied from squamoso stratified to cylindrical pseudostratified, with propria lamina rich in mucoserosas glands. With the exception of epiglottic cartilage, predominantly elastic, the rest are hyaline. The larynx of D. novemcinctus, although the same number of cartilages, differs morphologically and microscopically from the larynx of other species.