part of overlaps develops from start stage end stage retroarticular The retroarticular is a cartilage bone that forms at the posteroventral tip of Meckel's cartilage where the interoperculomandibular ligament attaches (5.1 mm NL). In the adult it is basically triangular in shape. The retroarticular is ligamentously connected to the interopercle and preopercle posteriorly and abuts the ventral shelf of the dentary anteriorly. ZFA:0000422 TAO:0000422 retroarticulars zebrafish_anatomy ventral mandibular arch endochondral bone anguloarticular-retroarticular joint retroarticular process larval:day 5 adult