The part of the skull in front of the eyes is rather short, but the rear part is long, with elongated temporal fenestrae (holes in the back of the skull).
As a whole the skull is triangular in shape.
The lower temporal fenestrae, on the sides of the skull, are very large, about a quarter the length of the entire skull.
The premaxillae are not fused together, and each possess a large fang seemingly formed from three fused teeth.
The front part of the premaxilla is very short, but the rear part is long, excluding the maxilla from the long nares (nostril holes).
Each maxilla possesses about thirteen or fourteen acrodont teeth which are fused to the bone (as is typical for rhynchocephalians).
The first six or seven teeth are tiny and simple.
However, the latter seven are much larger and more complex.
These teeth increase in size towards the back of the skull and possess a pointed cusp followed by a low ridge.

The nasal bones on the top of the snout are thin and separate from each other at the back of the snout to make room for the triangular front edge of the frontals.
The bones of the skull roof (frontals and parietals) are not fused to their respective pairs, and the parietals form a sagittal crest between the upper temporal fenestrae on the top of the skull.
The parietal foramen (a hole which holds the "third eye" in modern tuataras) is teardrop-shaped.
The postorbital, jugal, and squamosal bones on the side of the head curve upwards to form the bar between the upper and lower temporal fenestrae.
The jugal lacks a "subtemporal extension" forming the bottom edge of the lower temporal fenestra, leaving the hole open from the bottom as if it was an arch.
The squamosal also forms a large portion of the part of the skull behind the lower temporal fenestra, along with a thin and tall quadratojugal and a curved quadrate which probably supported a tympanic membrane (eardrum).

The bones of the roof of the mouth are mostly obscured, but were partially revealed by a micro-CT scan of the specimen.
Each of the palatines possess a row of teeth, although the form of such teeth cannot be determined.
The palatines themselves are separated by the long and thin front parts of the pterygoids, which do not seem to possess teeth.

The lower jaw is more shallow than those of other advanced sphenodontians, but not as much as that of Pleurosaurus.
It is smoothly curved, with the front tip at a higher level than the lower edge.
The front part of the jaw is toothless, but the rear part has a row of teeth.
Each tooth possesses a cusp preceded by a long ridge and followed by a short ridge.
The outer edge of the teeth have been partially worn away by contact with the maxillary teeth.
The part of the skull in front of the eyes is rather short, but the rear part is long, with elongated temporal fenestrae (holes in the back of the skull). As a whole the skull is triangular in shape. The lower temporal fenestrae, on the sides of the skull, are very large, about a quarter the length of the entire skull. The premaxillae are not fused together, and each possess a large fang seemingly formed from three fused teeth. The front part of the premaxilla is very short, but the rear part is long, excluding the maxilla from the long nares (nostril holes). Each maxilla possesses about thirteen or fourteen acrodont teeth which are fused to the bone (as is typical for rhynchocephalians). The first six or seven teeth are tiny and simple. However, the latter seven are much larger and more complex. These teeth increase in size towards the back of the skull and possess a pointed cusp followed by a low ridge.
The nasal bones on the top of the snout are thin and separate from each other at the back of the snout to make room for the triangular front edge of the frontals. The bones of the skull roof (frontals and parietals) are not fused to their respective pairs, and the parietals form a sagittal crest between the upper temporal fenestrae on the top of the skull. The parietal foramen (a hole which holds the "third eye" in modern tuataras) is teardrop-shaped. The postorbital, jugal, and squamosal bones on the side of the head curve upwards to form the bar between the upper and lower temporal fenestrae. The jugal lacks a "subtemporal extension" forming the bottom edge of the lower temporal fenestra, leaving the hole open from the bottom as if it was an arch. The squamosal also forms a large portion of the part of the skull behind the lower temporal fenestra, along with a thin and tall quadratojugal and a curved quadrate which probably supported a tympanic membrane (eardrum).
The bones of the roof of the mouth are mostly obscured, but were partially revealed by a micro-CT scan of the specimen. Each of the palatines possess a row of teeth, although the form of such teeth cannot be determined. The palatines themselves are separated by the long and thin front parts of the pterygoids, which do not seem to possess teeth.
The lower jaw is more shallow than those of other advanced sphenodontians, but not as much as that of Pleurosaurus. It is smoothly curved, with the front tip at a higher level than the lower edge. The front part of the jaw is toothless, but the rear part has a row of teeth. Each tooth possesses a cusp preceded by a long ridge and followed by a short ridge. The outer edge of the teeth have been partially worn away by contact with the maxillary teeth.
Vadasaurus