The body is covered with massive bony plates set close together and lying flat over the surface from head to tip of tail.

While the stegosaur's body was narrow and compressed, in this animal it is exceptionally broad and the wide spreading ribs are coossified with the vertebrae, making a very solid support for the transverse rows of armor plates.

The head is broad triangular, flat topped and solidly armored, the plates consolidated with the surface of the skull and overhanging sides and front, the nostrils and eyes overhung by plates and bosses of bone; and the tail ended in a blunt heavy club of massive plates consolidated to each other and to the tip of the tail vertebrae.

The legs were short, massive and straight, ending probably in elephant-like feet.

The animal has well been called "the most ponderous animated citadel the world has ever seen" and we may suppose that when it tucked in its legs and settled down on the surface it would be proof even against the attacks of the terrible Tyrannosaur.
[Illustration: Fig.