part of part of embryonic structure pharyngeal arch 1 1st arch mandibular component UBERON:0007237 EHDAA:583 relationship to Meckel's cartilage to be added Subsequent vertebrate evolution has also involved major alterations to the pharynx; perhaps the most notable occurred with the evolution of the gnathostomes. This involved substantial modifications to the most anterior pharyngeal segments, with the jaw forming from the first, anterior, pharyngeal segment, while the second formed its supporting apparatus, the hyoid.[well established][VHOG] EHDAA2:0000031 EMAPA:16382 ventral mandibular arch ventral visceral arch 1 VHOG:0000510 ventral pharyngeal arch 1