REYNCHOCEPHALIA 



i8i 



To the student of paleontology these animals are of interest 

 because of the retention of several primitive traits which had long 



Fig. 89. — Champsosawus ; skull from above. (After Brown) 



disappeared in other known reptiles. While the vertebrae had 

 ceased to be perforated by the notochord, as in the early reptiles, 

 they were still shallowly biconcave. The first bone of the neck, 



