Ancylostomatidae Looss, 1905 (habitat flag source)
Angiostomatidae Blanchard, 1895 (habitat flag source)
Brevibuccidae Paramonov, 1956 (habitat flag source)
Bunonematidae Paramonov, 1956 (habitat flag source)
Carabonematidae Stammer & Wachek, 1952 (habitat flag source)
Chambersiellidae Thorne, 1937 (habitat flag source)
Criconematidae Taylor, 1936 (habitat flag source)
Diaphanocephalidae Travassos, 1920 (habitat flag source)
Dictyocaulidae Skrjabin, 1933 (habitat flag source)
Elaphonematidae Heyns, 1962 (habitat flag source)
Fergusobiidae accepted as Neotylenchidae Thorne, 1941 (habitat flag source)
Globocephalidae Travassos & Vogelsang, 1932 accepted as Ancylostomatidae Looss, 1905 (habitat flag source)
Heteroderidae Filipjev, 1934 (habitat flag source)
Iotonchiidae Goodey, 1953 (habitat flag source)
Metastrongylidae Leiper, 1908 (habitat flag source)
Odontorhabditidae accepted as Rhabditidae Örley, 1880 (habitat flag source)
Ollulanidae (habitat flag source)
Pratylenchidae Thorne, 1949 (habitat flag source)
Pseudodiplogasteroididae De Ley & Blaxter, 2002 (habitat flag source)
Pterygorhabditidae Goodey, 1963 (habitat flag source)
Rhabditonematidae Andrássy, 1976 (habitat flag source)
Robertiidae Travassos & Kloss, 1960 accepted as Traklosiidae Bernard & Phillips, 2015 (habitat flag source)
Sphaerulariidae Lubbock, 1861 (habitat flag source)
Strongylacanthidae (habitat flag source)
Strongylidae Baird, 1853 (habitat flag source)
Strongyloididae Chitwood & McIntosh, 1934 (habitat flag source)
Syngamidae Leiper, 1912 (habitat flag source)
Syrphonematidae Laumond & Lyon, 1971 (habitat flag source)
Trichostrongylidae Leiper, 1908 (habitat flag source)
Tylenchulidae Skarbilovitch, 1947 (habitat flag source)