TABLE 4. Summary of the relationship between skull bones in Sphenodon.

	Bone	Number of joints	Most substantial joint	Bones
	premaxilla	4	nasal	premaxilla, nasal, maxilla, vomers
	maxilla	6	jugal	premaxilla, nasal, prefrontal, palatine, ectopterygoid, jugal
	septomaxilla	3	maxilla	premaxilla, maxilla, vomer
	nasal	4	frontal	premaxilla, nasal, prefrontal, frontal
	prefrontal	4	frontal	nasal, prefrontal, maxilla, palatine
	frontal	5	postfrontal	frontal, nasal. prefrontal, postfrontal, parietal
	palatine	6	maxilla or prefrontal	maxilla, prefrontal, vomers, pterygoid, ectopterygoid (very weak), jugal
	vomers	4	palatines	premaxilla, vomer, palatines, pterygoid
	pterygoid	7	ectopterygoid	vomers, palatines, quadrate, ectopterygoid, pterygoid, squamosal, braincase (basisphenoidl)
	ectopterygoid	3	pterygoid	pterygoid, maxilla, jugal
	epipterygoid	3	pterygoid	pterygoid, quadrate, braincase (prootic)
	jugal	7	maxilla	maxilla, ectopterygoid, postorbital, quadratojugal, squamosal, palatine
	postorbital	3	jugal	jugal, postfrontal, squamosal
	postfrontal	3	frontal	parietal, frontal, postorbital
	parietal	5	postfrontal	frontal, postorbital, squamosal, parietal, braincase (supraoccipital)
	squamosal	7	quadrate	jugal, quadratojugal, postorbital, parietal, quadrate, pterygoid, braincase (opisthotic)
	quadratojugal	3	quadrate	quadrate, jugal, squamosal
	quadrate	3	pterygoid	pterygoid, quadratojugal, squamosal
	braincase	3	parietal	parietal, pterygoid, squamosal