part of develops from embryonic maxillary segment sense organ maxillary sensory complex primordium embryonic maxillary sensory complex Sense organ of the embryonic maxillary segment that gives rise to the terminal organ of the larval head. It is posterior and ventral to the embryonic brain by stage 13 and migrates ventrally and anteriorly to establish its final position, ventral to the dorsal organ, by stage 17. FBbt:00005618 VFB:FBbt_00005618 fly_anatomy.ontology embryonic terminal organ dorsal ectoderm derivative