Living members vary in head and body length from about 125 mm for Chlamyphorus to 1,200 mm for the giant anteater, Myrmecophaga. The hand usually has two or three digits that are much larger than the others, when present, and all the fingers have long, sharp, strong claws. The foot usually has five toes. The bones of the lower arm are separate, whereas the bones of the lower leg are either separate, united at the ankle, or joined at both ends. The mammae are located near the armpit, on the chest, or on the abdomen.
Females have a common urinary and genital duct.
The testes are located in the abdominal cavity between the rectum and the urinary bladder. Xenarthrans have a double posterior vena cava that returns blood from the posterior part of the body to the heart, whereas most other mammals have only a single vena cava. The skull is very elongated in anteaters but short and rounded in sloths. The neck vertebrae vary in number from six to nine, and the pelvis is narrow and elongate. Although the former technical designation of this order, Edentata, signifies toothlessness, only the anteaters actually have no teeth.