Gordioida is een klasse van paardenhaarwormen (Nematomorpha). De soorten in deze klasse zijn gerelateerd aan hun voorkomen in of nabij zoet water. In Nederland komt één soort voor, de Gordius setiger.

Taxonomie 
 Orde Chordodea
 Familie Chordodidae
 Geslacht Chordodes
 Chordodes aelianus - (Camerano, 1894)
 Chordodes aethiopicus - Inoue, 1974
 Chordodes africanus - Sciacchitano, 1933
 Chordodes albibarbatus - Montgomery, 1898 
 Chordodes ambonensis  - Sciacchitano, 1962 
 Chordodes anthophorus - Kirjanova, 1950 
 Chordodes auranthiacus - von Linstow, 1906 
 Chordodes balzani - Camerano, 1896 
 Chordodes baramensis - Römer, 1895 
 Chordodes betularius - Linstow, 1904 
 Chordodes bipilus - Kirjanova, 1957 
 Chordodes boulengeri - Camerano, 1912 
 Chordodes bouvieri -  (Villot, 1885) Römer, 1859 
 Chordodes brasiliensis - Janda, 1894 
 Chordodes brevipilus - Schmidt-Rhaesa, 2002 
 Chordodes bukavuensis - Sciacchitano, 1958 
 Chordodes caledoniensis - (Villot, 1874) Römer, 1896 
 Chordodes capensis - Camerano, 1859 
 Chordodes capillatus - Linstow, 1901 
 Chordodes carmelitanus - Carvalho and Feio, 1950 
 Chordodes clavatus - Linstow, 1906 
 Chordodes compactus - Schmidt-Rhaesa and Brune, 2008 
 Chordodes compressus - Römer, 1895 
 Chordodes congolensis - Sciacchitano, 1933 
 Chordodes corderoi - Carvalho, 1946 
 Chordodes cornuta  - Villalobos and Camino, 1999 
 Chordodes cubanensis - Montgomery, 1898 
 Chordodes curvicillatus  - Kirjanova and Spiridonov, 1980 
 Chordodes defilippii - (Rosa, 1880) Römer, 1895 
 Chordodes devius  - Kirjanova, 1950 
 Chordodes digitatus - Linstow, 1901 
 Chordodes ferox - Camerano, 1897 
 Chordodes festae - Camerano, 1897 
 Chordodes fukuii - Inoue, 1951 
 Chordodes furnessi - Montgomery, 1898 
 Chordodes gariazzi - Camerano, 1902 
 Chordodes gestri - Camerano, 1904 
 Chordodes guineensis  - Spiridonov, 2002 
 Chordodes hawkeri - Camerano, 1902 
 Chordodes heinzei - Sciacchitano, 1937 
 Chordodes ikelensis - Sciacchitano, 1961 
 Chordodes insidiator - Camerano, 1899 
 Chordodes iturensis - Sciacchitano, 1958 
 Chordodes jandae - Camerano, 1895 
 Chordodes japonensis - Inoue, 1952 
 Chordodes joyeuxi - Dorier, 1935 
 Chordodes kakandensis - Sciacchitano, 1958 
 Chordodes kallstenii - Jagerskiöld, 1897 
 Chordodes kivuensis - Sciacchitano, 1958 
 Chordodes kolensis - Sciacchitano, 1933 
 Chordodes koreensis - Baek, 1993 
 Chordodes lefeburi - (Sciacchitano, 1937) 
 Chordodes lenti - Carvalho, 1944 
 Chordodes ligasiensis  - Sciacchitano, 1933 
 Chordodes lotus - de Villalobos and de Miralles, 1997 
 Chordodes maculatus - Sciacchitano, 1958 
 Chordodes madagascariensis - Camerano, 1897 
 Chordodes matensis - de Villalobos and de Miralles, 1997 
 Chordodes mobensis - Sciacchitano, 1958 
 Chordodes modiglianii - (Camerano, 1892) Camerano, 1897 
 Chordodes montgomeryi - Camerano, 1901 
 Chordodes moraisi - (Carvalho, 1942) Carvalho, 1944 
 Chordodes morgani - Montgomery, 1898 
 Chordodes moutoni - Camerano, 1895 
 Chordodes muelleri - Sciacchitano, 1937 
 Chordodes nobilii - Camerano, 1901 
 Chordodes ornatus - (Grenacher, 1868) 
 Chordodes parasitus - Creplin, 1847 
 Chordodes penicillatus - Camerano, 1895 
 Chordodes peraccae - (Camerano, 1894)
 Chordodes pilosus - Möbius, 1855 
 Chordodes pollonerae  - Camerano, 1912 
 Chordodes polycoronatus - Schmidt-Rhaesa and Brune, 2008 
 Chordodes polytuberculatus - Schmidt-Rhaesa and Menzel, 2005 
 Chordodes puncticulatus - Camerano, 1895 
 Chordodes queenslandi - Schmidt-Rhaesa, 2002 
 Chordodes rigatus - Sciacchitano, 1937 
 Chordodes ruandensis - Sciacchitano, 1937 
 Chordodes sajanensis - Spiridonov, 2000 
 Chordodes sandoensis - Sciacchitano, 1937 
 Chordodes schoutedeni - Sciacchitano, 1933 
 Chordodes shipleyi - Camerano, 1899 
 Chordodes siamensis - Camerano, 1903 
 Chordodes silvestri - Camerano, 1895 
 Chordodes skorikovi -  Camerano, 1903 
 Chordodes staviarskii - Carvalho and Feio, 1950 
 Chordodes tenodarae  - Kirjanova, 1957 
 Chordodes timorensis - Camerano, 1895 
 Chordodes tuberculatus - Linstow, 1901 
 Chordodes villalobi - Schmidt-Rhaesa and Brune, 2008 
 Chordodes wangi - Wu and Tang, 1933 
 Geslacht Euchordodes
 Euchordodes libellulovivens - Heinze, 1937 
 Euchordodes malaysiensis - Inoue, 1966 
 Euchordodes nigromaculatus - Poinar, 1991 
 Geslacht Neochordodes
 Neochordodes australis - de Miralles and de Villalobos, 1996 
 Neochordodes bonaerensis - de Miralles and de Villalobos, 1998 
 Neochordodes californensis - de Miralles and de Villalobos, 1995 
 Neochordodes chordodides - Schmidt-Rhaesa and Menzel, 2005 
 Neochordodes columbianus  - Faust and Ramos, 1960 
 Neochordodes occidentalis - (Montgomery, 1898) Poinar and Doleman, 1974 
 Neochordodes nietoi - De Miralles and De Villalobos, 1994 
 Neochordodes occidentalis - (Montgomery, 1898) 
 Neochordodes punctatus - De Miralles and De Villalobos, 1996 
 Neochordodes semiluna  - Villalobos and Camino, 1999 
 Neochordodes serranensis - De Miralles and De Villalobos, 1996 
 Neochordodes torrenticola - De Miralles and De Villalobos, 1996 
 Neochordodes uniareolatus - Carvalho, 1946 
 Geslacht Pantachordodes
 Pantachordodes europaeus - (Heinze, 1952)
 Geslacht Pseudochordodes 
 Pseudochordodes bedriagae - (Camerano, 1896) 
 Pseudochordodes bulbareolatus - Schmidt-Rhaesa and Menzel, 2005 
 Pseudochordodes dugesi - (Camerano, 1898) 
 Pseudochordodes gordioides - (Montgomery, 1898) de Miralles et al., 1997 
 Pseudochordodes griffini - (Camerano, 1898) 
 Pseudochordodes guatemalensis - De Miralles et al., 1997 
 Pseudochordodes manteri - Carvalho, 1942 
 Pseudochordodes meridionalis - Carvalho and Feio, 1950 
 Pseudochordodes pardalis - (Camerano, 1893) 
 Pseudochordodes texanus - Schmidt-Rhaesa et al., 2003 
 Familie Parachordodidae
 Geslacht Beatogordius
 Beatogordius abaiconus - Carvalho, 1946 
 Beatogordius abbreviatus - (Villot, 1874) de Miralles, 1984 
 Beatogordius alfredi - (Camerano, 1894)
 Beatogordius australiensis - Schmidt-Rhaesa and Bryant, 2004 
 Beatogordius brieni - Sciacchitano, 1961 
 Beatogordius deshayesi - (Villot, 1874)
 Beatogordius echinatus - (Linstow, 1901) Schmidt-Rhaesa and de Villalobos, 2001 
 Beatogordius erythraeus - (Camerano, 1915) Sciacchitano, 1940 
 Beatogordius funis - de Villalobos et al., 2003 
 Beatogordius inesae - (Cavalieri, 1961) Miralles, 1984 
 Beatogordius irregularis - Miralles, 1972 
 Beatogordius latastei - (Camerano, 1895) Heinze, 1934 
 Beatogordius lineatus - Schmidt-Rhaesa and Bryant, 2004 
 Beatogordius palustre - de Villalobos et al., 2003 
 Beatogordius raphaelis - (Camerano, 1893) Sciacchitano, 1937 
 Beatogordius regularis - Heinze, 1934 
 Beatogordius sankurensis - Sciacchitano, 1958 
 Beatogordius ugandensis - Schmidt-Rhaesa and de Villalobos, 2001 
 Beatogordius variabilis - Miralles, 1981 
 Beatogordius wilsoni - Sciacchitano, 1958 
 Geslacht Gordionus
 Gordionus alascensis - (Montgomery, 1907) Schmidt-Rhaesa et al., 2003 
 Gordionus alpestris - (Villot, 1885) Heinze, 1937 
 Gordionus annamensis - Spiridonov, 1993 
 Gordionus austriacus - Heinze, 1952
 Gordionus austrinus - de Villalobos, Zanca and Ibarra-Vidal, 2005 
 Gordionus barbatus - Schmidt-Rhaesa and Cieslak, 2008 
 Gordionus bilinareolatus - (Heinze, 1937) Heinze 1941 
 Gordionus blanchardi - (Villot, 1874) 
 Gordionus brunneus - Monten, 1951 
 Gordionus capitosulcatus - (Montgomery, 1898) Heinze, 1935 
 Gordionus chinensis - (Villot, 1874) 
 Gordionus conglomeratus - Heinze, 1952
 Gordionus cyrnensis - Giudicelli and Nicoli, 1962 
 Gordionus densareolatus  - (Montgomery, 1898) 
 Gordionus diligens - de Villalobos et al., 1999 
 Gordionus divergens - Schuurmanns Steckhoven, 1943 
 Gordionus dubiosus - Henze, 1937 
 Gordionus enigmaticus - de Villalobos, Zanca and Ibarra-Vidal, 2005 
 Gordionus formidatus - Havlik, 1954 
 Gordionus fragmentarius - Heinze, 1952
 Gordionus harpali - Heinze, 1940 
 Gordionus kaschgaricus - (Camerano, 1897) Heinze, 1935 
 Gordionus kii - Schmidt-Rhaesa and Sato, 2009 
 Gordionus lapponicus - Monten, 1951 
 Gordionus lenae - Heinze, 1937 
 Gordionus lineatus - (Leidy, 1851) Schmidt-Rhaesa et al., 2003 
 Gordionus linourgos - de Villalobos et al., 1999 
 Gordionus longareolatus - (Montgomery, 1898) Schmidt-Rhaesa et al., 2003 
 Gordionus longistriatus - Schmidt-Rhaesa, 2004 
 Gordionus lunatus - Müller, 1927 
 Gordionus meissneri - Müller, 1927 
 Gordionus molopsis - Heinze, 1937 
 Gordionus ondulatus - Miralles, 1984 
 Gordionus perronciti - (Camerano, 1887) 
 Gordionus platycephalus - (Montgomery, 1898) Heinze, 1935
 Gordionus porosus - de Villalobos and Voglino, 2000
 Gordionus preslii - (Vejdovsky, 1886)
 Gordionus prismaticus - (Villot, 1874) Heinze, 1935
 Gordionus punctulatus - Heinze, 1937
 Gordionus reticulates - (Villot, 1874)
 Gordionus roccatii - (Camerano, 1912) Heinze, 1935
 Gordionus rugosus - Canadjija, 1956
 Gordionus scaber - Müller, 1927
 Gordionus scripturus - Heinze, 1952
 Gordionus semistiatus - Heinze, 1937
 Gordionus senkovi - Malakhov and Spiridonov, 1982
 Gordionus silphae - Heinze, 1937
 Gordionus sinepilosus - Schmidt-Rhaesa et al., 2003
 Gordionus stenobothri - Canadjija, 1956
 Gordionus strigatus - Müller, 1927
 Gordionus subalpinus - Heinze, 1952
 Gordionus sulcatus - Heinze, 1937
 Gordionus thiemanni - Heinze, 1937
 Gordionus thuringensis - Müller, 1927
 Gordionus turkensis - Schmidt-Rhaesa and Cieslak, 2008
 Gordionus violaceus - (Baird, 1853) Müller, 1927
 Gordionus wolterstorffii - (Camerano, 1888) Heinze, 1937
 Geslacht Parachordodes
 Parachordodes aequatorialis - Sciacchitano, 1937
 Parachordodes annulatus - Linstow, 1906
 Parachordodes arndti - Heinze, 1935
 Parachordodes bourguignoni - Sciacchitano, 1937 
 Parachordodes capitosulcatus - (Montgomery, 1898) Heinze, 1935 
 Parachordodes ciferrii - Sciacchitano, 1932 
 Parachordodes coreanus - Linstow, 1906 
 Parachordodes densareolatus - (Montgomery, 1898) Camerano, 1915 
 Parachordodes diblastus - (Örley, 1881) Schmidt-Rhaesa, 2008 
 Parachordodes gemmatus - (Villot, 1885) Camerano, 1897 
 Parachordodes lestici - Heinze, 1935 
 Parachordodes maculatus - A (Linstow, 1883) Linstow, 1905 
 Parachordodes magnus - Spiridonov, 1989 
 Parachordodes megareolatus  - Schmidt-Rhaesa, Chung 
 Parachordodes modestus - Spiridonov, 1989 
 Parachordodes okadai  - Inoue, 1955 
 Parachordodes orientalis  - Fukui and Inoué, 1940 
 Parachordodes pleskei - (Camerano, 1986) 
 Parachordodes propareolatus - Heinze, 1935 
 Parachordodes pustulosus - (Baird, 1853) Camerano, 1897 
 Parachordodes sciacchitanoi - Heinze, 1935 
 Parachordodes sjöstedti - Camerano, 1910 
 Parachordodes speciosus  - (Janda, 1894) Heinze, 1935 
 Parachordodes tegonotus - Poinar et al., 2004 
 Parachordodes tolosanus - (Dujardin, 1842) Camerano, 1897 
 Geslacht Paragordionus
 Paragordionus bohemicus - Havlik, 1947 
 Paragordionus dispar - (Müller, 1927) Heinze, 1935 
 Paragordionus ibericus - Schmidt-Rhaesa and Cieslak, 2008 
 Paragordionus kawamurai  - Yamaguti, 1943 
 Paragordionus rautheri - Heinze, 1937 
 Paragordionus vejdovskyi - (Janda, 1895) Heinze, 1935 
 Geslacht Semigordionus
 Semigordionus circumannulatus - Heinze, 1952
 Familie Paragordiidae
 Geslacht Paragordius
 Paragordius andreasii - Zanca and de Villalobos, 2006 
 Paragordius areolatus - Linstow, 1906 
 Paragordius aurantiacus - Linstow, 1906 
 Paragordius cinctus - Linstow, 1906 
 Paragordius dartevellei - Sciacchitano, 1958 
 Paragordius diversolobatus  - Heinze, 1935 
 Paragordius emeryi - (Camerano, 1895) Camerano, 1895 
 Paragordius esavianus - Carvalho, 1942 
 Paragordius flavescens - Linstow, 1906 
 Paragordius laurae - Sciacchitano, 1958 
 Paragordius marlieri - Sciacchitano, 1958 
 Paragordius minusculus - Carvalho, 1944 
 Paragordius mulungensis - Sciacchitano, 1958 
 Paragordius somaliensis - Sciacchitano, 1962 
 Paragordius stylosus - (Linstow, 1883) Camerano, 1897 
 Paragordius tanganikensis - Sciacchitano, 1958 
 Paragordius tricuspidatus - (Dufour, 1828) Camerano, 1897 
 Paragordius varius - Leidy, 1851 
 Familie Spinochordodidae
 Geslacht Spinochordodes
 Spinochordodes actiniphorus  - Kirjanova, 1950 
 Spinochordodes bacescui - (Capuse, 1965) Zanca and Schmidt-Rhaesa, 2006 
 Spinochordodes baeri  - (Camerano, 1896) 
 Spinochordodes cameranoi  - Kirjanova, 1950 
 Spinochordodes europaeus - (Heinze, 1952)
 Spinochordodes piliferus  - Kirjanova, 1950 
 Spinochordodes skrjabini - Kirjanova, 1958 
 Spinochordodes tellinii - (Camerano, 1888) Kirjanova, 1950 
 Spinochordodes vitiferus  - Kirjanova, 1950
 Orde Gordea
 Familie Gordiidae
 Geslacht Acutogordius - Heinze, 1952
 Acutogordius acuminatus - de Miralles and de Villalobos, 1998
 Acutogordius americanus - de Miralles and de Villalobos, 1998
 Acutogordius australiensis - Spiridonov, 1984
 Acutogordius doriae - (Camerano, 1890)
 Acutogordius feae - (Camerano, 1897)
 Acutogordius incertus - (Villot, 1874)
 Acutogordius obesus - (Camerano, 1895) de Miralles and de Villalobos, 1998
 Acutogordius protectus - Schmidt-Rhaesa and Geraci, 2006
 Acutogordius sulawensis - Schmidt-Rhaesa and Geraci, 2006
 Geslacht Gordius
 Gordius albopunctatus - Müller, 1927 
 Gordius alpinus  - Spiridonov, 1998 
 Gordius amoyensis - Tang, 1934 
 Gordius angulatus - Linstow, 1906 
 Gordius aquaticus - Linnaeus, 1758 
 Gordius attoni - Redlich, 1980 
 Gordius austrinus - De Villalobos, Zanca and Ibarra-Vidal, 2005 
 Gordius bivittatus  - Kirjanova, 1949 
 Gordius borisphaenicus - Spiridonov, 1984 
 Gordius cavernarum - Inoue, 1972 
 Gordius cognetti - Camerano, 1904 
 Gordius corrugatus - Camerano, 1895 
 Gordius dectici - Heinze, 1937 
 Gordius deltaensis - de Miralles and de Villalobos, 1996 
 Gordius difficilis - (Montgomery, 1898) Smith, 1994 
 Gordius dimorphus - Poinar, 1990 
 Gordius elongiporus - Schmidt-Rhaesa, 2000 
 Gordius emarginatus - Villot, 1885 
 Gordius flavus - Linstow, 1906 
 Gordius foochowensis - Tang, 1934 
 Gordius fulgur - Baird, 1861 
 Gordius georgensis - Kirjanova, 1955 
 Gordius germanicus - Heinze, 1937 
 Gordius gesneri - Heinze, 1937 
 Gordius guatemalensis  - Linstow, 1902 
 Gordius heinzei - Schuurmans Steckhoven, 1943 
 Gordius hispidus - Linstow, 1906 
 Gordius horsti - Camerano, 1895 
 Gordius impressus - Schneider, 1866 
 Gordius interjectus  - Heinze, 1940 
 Gordius isohypsatus - Canadjija, 1956 
 Gordius japonicus  - Inoue and Fukui, 1953 
 Gordius jarulini - Zakarijew, 1967 
 Gordius kimmeriensis - Spiridonov, 1998 
 Gordius labidus - de Miralles and de Villalobos, 1996 
 Gordius lapponicus - Linstow, 1906 
 Gordius lineatus - Baek and Noh, 1992 
 Gordius locustae - Havlik, 1954 
 Gordius longiformis - Heinze, 1934 
 Gordius longissimus - Römer, 1895 
 Gordius lumpei - Müller, 1927 
 Gordius luteopunctatus  - Inoue, 1979 
 Gordius meruanus - Camerano, 1910 
 Gordius mongolicus - Spiridonov, 1998 
 Gordius mosaicus - Canadjija, 1956 
 Gordius mülleri - Heinze, 1933 
 Gordius nonmaculatus - Heinze, 1937 
 Gordius ogatai  - Inoue, 1979 
 Gordius omensis  - Wu and Tang, 1933 
 Gordius panighettensis - Sciacchitano, 1955 
 Gordius paranensis - Camerano, 1892 
 Gordius paronae - Camerano, 1903 
 Gordius parvaquaticus - Heinze, 1952
 Gordius pavlovskii - Kirjanova, 1955 
 Gordius pioltii - Camerano, 1887 
 Gordius plicatissimus - Heinze, 1952
 Gordius pilicatulus - Heinze, 1937 
 Gordius polychaetus - Tang, 1934 
 Gordius robustus - Leidy, 1851 
 Gordius rosae - Camerano, 1887 
 Gordius salvadorii - Camerano, 1895 
 Gordius samoensis - Linstow, 1906 
 Gordius setiger - Schneider, 1866 
 Gordius sinareolatus - Havlik, 1949 
 Gordius solaris  - Kirjanova, 1950 
 Gordius spinosus - De Miralles and De Villalobos, 1996 
 Gordius stellatus - Linstow, 1906 
 Gordius tatrensis - Janda, 1894 
 Gordius testaceus  - Kirjanova, 1949 
 Gordius tirolensis - Heinze, 1937 
 Gordius toschii - Sciacchitano, 1940 
 Gordius tuberculatus - Canadjija, 1956 
 Gordius turcomanicus - Spiridonov, 1998 
 Gordius undulatus - Heinze, 1937 
 Gordius valnoxius - Degrange and Martinot, 1995 
 Gordius villoti - Rosa, 1882 
 Gordius willeyi - Camerano, 1899 
 Gordius zammaranoi - Sciacchitano, 1932 
 Gordius zavattarii - Camerano, 1908 

Paardenhaarwormen