PRIMARY MANDIBLE
Meckel\'s cartilage (the functional lower jaw of Elasmobranchii and Holocephali, the embryonic lower jaw of other gnathostomous vertebrates which ossifies at least in part as the mentomeckelian, mediomeckelian, coronomeckelian, articular and retroarticular. It remains in some adult fishes as a pointed rod embedded in the dentary and angular. Also called mandibular cartilage and ceratomandibular cartilage. See also Bridge\'s ossicles)