With a length of about 50 centimetres (20 in), the skull of Zuul is of considerable size, being only surpassed among the ankylosaurs of Laramidia (western North America) by the three known skulls of Ankylosaurus, specimens AMNH 5214, AMNH 5895 and CMN 8880.
The skull is also rather flat but this is partly caused by compression.
The snout is wide and truncated at the front.
The bony nostrils are pointing to the front.
In each nostril only a single nasal opening is visible, perhaps homologous to "Aperture A" in related species.

Behind a narrow pair of nasal armour plates, rows of caputegulae stretch to the rear.
The two front rows consists of pairs of rectangular plates.
Part of the third row is a small central hexagonal caputegula.
More to the back, the osteoderms all become square or hexagonal in profile and more strongly imbricating.
Above the eye socket the front and rear supraorbitals form a sharp edge, protruding sideways.
Deep in each eye socket, a bony plate is present.
Similar plates in specimens of Euoplocephalus and Dyoplosaurus were reported by Walter Preston Coombs as bony eyelids.
The squamosal horns on the rear corners of the skull roof are robust and pyramidal in shape.
They have a sharp keel on top and deep grooves running towards the tip.
The quadratojugal horns on the lower cheeks are also robust, with a convex front edge and a straight rear edge.
They ware seen as being mainly outgrowths of the quadratojugal bones themselves.
With a length of about 50 centimetres (20 in), the skull of Zuul is of considerable size, being only surpassed among the ankylosaurs of Laramidia (western North America) by the three known skulls of Ankylosaurus, specimens AMNH 5214, AMNH 5895 and CMN 8880. The skull is also rather flat but this is partly caused by compression. The snout is wide and truncated at the front. The bony nostrils are pointing to the front. In each nostril only a single nasal opening is visible, perhaps homologous to "Aperture A" in related species.
Behind a narrow pair of nasal armour plates, rows of caputegulae stretch to the rear. The two front rows consists of pairs of rectangular plates. Part of the third row is a small central hexagonal caputegula. More to the back, the osteoderms all become square or hexagonal in profile and more strongly imbricating. Above the eye socket the front and rear supraorbitals form a sharp edge, protruding sideways. Deep in each eye socket, a bony plate is present. Similar plates in specimens of Euoplocephalus and Dyoplosaurus were reported by Walter Preston Coombs as bony eyelids. The squamosal horns on the rear corners of the skull roof are robust and pyramidal in shape. They have a sharp keel on top and deep grooves running towards the tip. The quadratojugal horns on the lower cheeks are also robust, with a convex front edge and a straight rear edge. They ware seen as being mainly outgrowths of the quadratojugal bones themselves.
Zuul