It lived from the Late Miocene to the Early Pliocene, and its fossilized remains were discovered in South America.

Like all glyptodonts, this animal had a robust carapace, formed by osteoderms fused together, covering a large part of its body.

Phlyctaenopyga was a medium-sized glyptodont, not exceeding two meters in length.

Phlyctaenopyga was a glyptodont, a clade of cingulates related to the modern armadillos, with a rigid carapace.

Phlyctaenopyga seems to have been close to the genera Nopachthus and Plohophorus, within the tribe Sclerocalyptini.