Even though its name means “stiff lizard,” they were also called “armored dinosaurs.” It lived in humid regions where it fed on low vegetation (ferns, grasses, etc.). Its stocky silhouette enabled it to confront predators. The back, flanks, neck, and tail were covered with a thick armor made up of numerous flat bony plates interlocked with each other and spines. At the end of the tail there was a bony mass formed from the fusion of osteoderms, vertebrae, and tendon. This mass could break bones. Bony protrusions around the eye sockets
helped protect the head. The bones of its head were fused with other bones of the skeleton, providing better resistance. Only the ventral part did not have a defense system. That’s why it seems it would lay down on the ground during attacks to be completely safe.