Historically most significant taxonomic changes and modifications of Ulidiidae at the family level. Circles represent families or subfamilies. Dashed line corresponds to the position of Homalocephala throughout the development of the system. Dot-dashed line corresponds to the position of Seioptera throughout the development of the system. Rectangles combine subfamilies or groups into families, where gray color denotes major classification trends. The arrow indicates inclusion of American species of Otitidae by Curran ([1934a], [b]) into Otitinae of the Ulidiinae + Otitinae group.