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

Plohophorus shared similarities with another Miocene glyptodont, Phlyctaenopyga, especially in its rather broad and low skull.

The ornamentation of the caudal tube, protecting the tail, was more simplified; the peripheral figures were partially regressed and marked in the distal part; the central oval-shaped figures were contiguous to each other and only left space for small triangular areas between each other.

The genus Plohophorus was first described in 1887 by Florentino Ameghino, based on fossil remains found in Upper Miocene terrains of Argentina.

The type species is Plohophorus figuratus; several other species from the Late Miocene and the Early Pliocene were also attributed to the genus, such as Plohophorus paranensis, P. sygmaturus, P. cuneiformis, P. coronatus, P. ameghini, P. araucanus, P. australis and P. orientalis.