StegocephalaSteg`o*ceph"a*la\, n. pl. [NL., fr. Gr. ? roof + ? head.] (Paleon.) An extinct order of amphibians found fossil in the Mesozoic rocks; called also Stegocephali, and Labyrinthodonta. Note: Their teeth, in transverse sections, usually show a labyrinthiform arrangement of the cement and dentine. The under side of the body was covered with bony plates. Some of the Stegocephala were of very large size, and the form of the body varied from short, stout forms to others that were as slender as serpents.