AND CLASSIFICATION OF THE FOSSIL RRPTILIA. 
287 
Relation hetween Dicynodon and Scelidosaurus, 
Scelidosaurus makes a certain approximation in some respects to the Dicynodont 
skull, but the resemblances are less important than might appear. Tims, though the 
quadrate bone is concealed, as in Dicynodonts, it is a long, comparatively slender bone, 
which is not in front of the squamosal, and not wedged into it, while the quadrato- 
jugal, which covers its distal end, is itself covered by the malar. Internally the 
quadrate of Scelidosaurus sends a long process inward, wliicli laps in front of the 
quadrate process of the pterygoid. Hence the forms and relations of the quadrate 
bone in the two types are altogether dissimilar. 
There is a certain resemblance in palatal structures, as may be seen from the 
accompanying restoration of the palate in Scelidosaurus. But the pterygoid bones of 
Fig. 6. 
Restoration of the palate of Scelidosaurus, from the specimen in the British Museum. 
the Ornithischian are not anchylosed ; and, although the bone has a similar posterior 
expansion in Dicynodon, and a similar pterygoid process, it possesses an external 
process which Dicynodon has not, and in front of that process there is a fragment 
which may be part of a transverse bone. If so, it was probably prolonged laterally to 
the malar, and not anteriorly, like the pterygoid of Dicynodon. Anterior to the 
pterygoid Scelidosaurus has a small ossification which appears to be a delicate palatine 
bone placed in the median line, and therefore unlike the lateral palatine of Dicynodon, 
