Alternative spelling: Trionychoidi
Parent taxon: Cryptodira according to J. R. Bourque et al. 2015
See also Carroll 1988, de Broin and de la Fuente 1993, Estes 1964, Gadow 1898, Gaffney 1975, Holman and Case 1988, Joyce 2007, Joyce et al. 2004, Karl 2007, Karl et al. 2006, Karl et al. 2012, Kuhn 1966, Lydekker 1889, Perrier 1928, Roxo 1937, Swinton 1934, Tong et al. 2010, van Dijk et al. 2014, Veress and Codrea 2020, Vremir 2013 and Zittel 1890
Sister taxa: Adocusia, Bashuchelyidae, Carettochelyoidea, Charitonyx tajanikolaevae, Chelonemydidae, Chelonioidea, Chelydridae, Chelydroidea, Chersidae, Chitracephalus, Cryptoderinea, Dermatochelydidae, Dermochelyoidea, Durocryptodira, Eucryptodira, Galvechelone, Glyptopidae, Glyptopsidae, Indochelyidae, Kallokibotioninae, Kayentachelyidae, Kinosternia, Kinosternoidae, Meiolanidae, Nanhsiungchelyidae, Panchelonioidea, Pantestudinoidea, Pantrionychia, Platysternoidea, Polysternum, Selmacryptodira, Trionychia, Trionychidae, Tritosternidae
Subtaxa: Adocidae Basilochelys Kinosternoidea Peltochelyidae Planetochelyidae Sinaspideretes
Type: Trionyx