Answer: labyrinthodont

AnswerCrossword Clue
labyrinthodontOf or relating to a group of large fossil amphibians of the late Devonian to early Triassic periods having such teeth
labyrinthodont(of teeth) Having the enamel deeply folded to form a labyrinthine structure
labyrinthodontan extinct amphibian, so called from a mazy pattern on a section of its teeth