Quick Definition
The main tooth-bearing bone of the lower jaw in bony fishes; equivalent to the mandible of mammals.
📖 Full Definition
The dentary is the anterior, tooth-bearing bone of the lower jaw (mandible) of bony fishes. Unlike in mammals (which fused all jaw bones into a single dentary-mandible), fish have several bones in the lower jaw: the dentary bears the main oral teeth, while the articular (or surangular) provides the jaw joint articulation with the quadrate of the upper jaw. The dentary teeth vary enormously: small conical teeth for gripping fish, molariform teeth for crushing molluscs, fang-like canines for subduing prey, or fused beak-like teeth in puffers and parrotfish.