External and digestive system morphology of the Tamandua tetradactyla

Collared anteater is present throughout the Brazilian territory, but its morphology is little known. This study aimed to trace its external biometric profile and its digestive system. Six cadavers (4 ± 0.16 kg) from Paraíba, Brazil, were used. The thoracic limbs were more robust when compared to pelvic. The length of the tail is below that described in specimens from south-eastern Brazil, probably due to the greater use of the tail suspension function in the leafier forests in this region. The tongue had no papillae and had keratinized squamous epithelium. The oesophagus was tubular with keratinized squamous epithelium. The stomach was single-chambered with simple prismatic epithelium and presence of tubular glands in the lamina propria. The pyloric region was thicker and had larger folds of mucosa; the greater curvature was approximately three times greater than the smaller. The small intestine was larger than that found in other Xernathra species such as sloth, an herbivore animal; in the large intestine, the caecum was small. The colon was subdivided ascending, transverse and descending, with simple prismatic epithelium. This study is the first to bring the description of the external and digestive system morphometrics of collared anteater adult and pup. The anatomical characteristics of the digestive system show that the digestion of the anteaters, although not using the fermentation, is not as rapid as in other Xenarthras, probably due to the material of the exoskeleton of the insects by them consumed. The data generate subsidies for the clinic, surgery, preservation and nutrition of this species.