crown height is about . The teeth have in total twelve to fourteen cusps on their edges. The cusp forming the tip of the tooth is off-set to behind. Around the neck of the crown, a thickened cingulum, or shelf, is present. Tail Of the remainder of the skeleton only the tail had been prepared in 2017. The tail has a total length of . The tail is divided into "free" front caudal vertebrae of the base and a "tail club" at the rear. In the latter organ Coombs distinguished again a "handle" and a "knob". The tail club, including the handle, has a length of , a record among North American ankylosaurids. In the handle, thirteen vertebrae are present. Probably another three are covered by the knob. To increase the chance of a damaging plastic deformation on impact of the knob, the handle is a stiff structure, the lack of flexibility caused by special connections between the vertebrae. The paired front joint processes, the prezygapophyses, are strongly elongated and overlap half of the preceding vertebra. They form a V-like structure, the branches angled at about 20°. Their joint facets are rotated to above and embrace the neural spine of the preceding vertebra. This spine is wedge-shaped and bent to behind with a flat top surface to fit into the V. This way a series of interlocking connections is formed, covering the entire top surface of the handle. The handle is further stiffened by bundles of ossified tendons, closely appressed to the vertebral sides. The tendons are over long and in diameter, with tapering ends. Along the sides of the handle runs a series of five pairs of osteoderms. Zuul is the first American ankylosaurid in which such handle osteoderms have actually been discovered; they had only been assumed for other species. On the free vertebrae of the tail base another three pairs are present. Between the large osteoderms smaller ossicles are positioned. The side tail osteoderms are flattened and have a triangular profile in top view, with a sharp point. Those more at the front have a sharper point, being longer than wide. They are almost shaped as an equilateral triangle with straight front and rear edges. More to behind the triangles are lower and wider. From the fifth pair onwards the front edges become longer and strongly concave, off-setting the point to the rear. The last pair, immediately