Anatomy
The ankylosaurs vertebral column consists of seven or eight cervicals, three or four sacrals, and approximately sixteen dorsals. Also, the ankylosaurids have twenty caudals as opposed to 40 or more in the polacanthids and nodosaurids. The reason for the difference in caudals is that the ankylosaurid’s caudals fuse together near the end of the tail producing an inflexible end for the club. Hence the name “fused lizard”. The ribs are angled upwards producing a more bulky, wider body. The region of the neck is generally short, while the trunk is very long. The pelvis is wide with the ilium rotated horizontally. Four or five dorsals have been fused to the sacrum preventing rotation of the pelvis giving it greater strength and stability. The limbs and feet of the ankylosaur are short and stout. Most of the animal’s immense weight is carried on the hind legs.