Strongylida Molin, 1861

Amidostomatidae Baylis & Daubney, 1926

Ancylostomatidae

Ancylostomidae

Angiostrongylidae

Chabertiidae

Cloacinidae

Cooperiidae

Crenosomatidae Schulz, 1951

Diaphanocephalidae

Dictyocaulidae

Filaroididae Schulz, 1951

Globocephalidae

Heligmonellidae

Heligmosomidae

Heligosomatidae

Heligosomidae

Herpetostrongylidae

Metastrongylidae

Molineidae

Ollulanidae

Ornithostrongylidae

Pharyngostrongylidae

Protostrongylidae

Pseudaliidae Railliet & Henry, 1909

Skrjabingylidae

Strongyidae

Strongylacanthidae

Strongylidae

Syngamidae

Trichostrongylidae

Uncinariidae