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

Proeuphractus had a carapace similar to that of modern armadillos, with complete mobile bands of osteoderms, allowing the animal to at least partially roll up.

The dermal osteoderms were robust and had the same basic ornamentation, except along the carapace axis, where the osteoderms presented a torsion of the central figure towards the postero-external corner, and were devoid of central follicle.

The genus Proeuphractus was first described in 1886 by Florentino Ameghino, based on fossil remains found in Argentina in Late Miocene terrains.

Proeuphractus was initially considered a member of the subfamily Euphractinae, close to the origin of the extant genus Euphractus (hence the genus name Proeuphractus), but more recent studies tends to indicate that it was nested at the basis of the subfamily Euphractinae, along with its relative Macroeuphractus.