part_of part of part of only in taxon developmentally induced by Eumetazoa Chordata multi-tissue structure pharyngeal arch http://upload.wikimedia.org/wikipedia/commons/8/8b/Gray41.png Numbered cranial to caudal. different in mammals. branchial arch = ZFA:0001613 pharyngeal arch 3-7. generally gill arch 1 = pharyngeal arch 3. terminology varies as to whether branchial arch follows gill or pharyngeal numbering early pharyngeal endoderm pharyngeal arch system embryonic head protuberance structure with developmental contribution from neural crest