Scanning electron microscopy of the lingual mucosa of the nine-banded armadillo, Dasypus novemcinctus.

The lingual mucosa of the nine-banded armadillo, Dasypus novemcinctus, was studied by scanning electron microscopy in order to analyse its morphology. The tongue of the armadillo is long and thin, and has filiform, fungiform and vallate papillae. In the anterior part of the tongue and near the vallate papillae, single or bifurcated filiform papillae are found. The vallate papillae are located on the dorsal surface of the middle third of the tongue, and have two or four slender extremities. The fungiform papillae are elliptical or rounded, and are concentrated mainly on the tip and lateral surface of the tongue, reaching as far as the middle third of the dorsal surface. Their surfaces are flat and smooth on the dorsal side, with some taste pores. Their taste buds are located near the vallum. In the material for which freeze-cracking was used, the epithelial layer showed a characteristic mucosal structure, with many epithelial papillae containing blood vessels and bundles of collagen fibers. The basal epithelial surface of the tongue mucosa showed irregular projections that are rounded or polygonal in shape, with a depression in the center. These depressions varied in diameter.