Giant Armadillo Mandible

Amadillos (and other xenarthrans) have simple, peg-like teeth. Lacking a branch-like or hooked root, teeth of an otherwise-preserved armadillo may simply fall out of the alveoli. It is common for a fossil jaw to be edentulous.

Amadillo teeth have no enamel. They grow continuously, they had to. Without enamel, they would have worn pretty quickly. They are open-rooted; that is, the tooth pulp-cavity was not closed as in many other taxa of mammals. Think of the continuously growing incisors of rodents and lagomorphs but without the enamel.

The term used to describe this condition is "hypselodonty" and is usually applied to mammal teeth. Hypselodont teeth are found in xenarthrans, rabbits, some rodents, and a few ungulates, according to Hulbert.