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. Its carapace was made of osteoderms whose central figure was surrounded by two or three rows of peripheral figures ; the second row was complete only in a few osteoderms in
Phlyctaenopyga ameghini, while the third row was always incomplete. The central figure of the osteoderms was convex and protruding, almost hemispherical. The skull was very short and broad, especially in the snout area. The osteoderms covering the head were practically devoid of ornamentation. ==Classification==