A type of tooth having an inwardly curved serrated shape; found in some dinosaurs, lizards and crocodils.
Zonal bone / Zonal growth
Bone material resulting from a pattern of development that involves slow to moderate growth at intermittent periods. Thus, zonal growth. Compare lamellar bone.
Usually peg-like bones that help to hold vertebra together and prevent them from slipping apart. (plur,zygapophyses) projections of bone on the anterior and posterior ends of a vertebra; these projections meet similar projections (zygapophyses) of the anterior and posterior to it.