Alternative spellings: Placodondia, Placodonti
Parent taxon: Sauropterygia according to W. Wang et al. 2019
See also Carroll 1988, Gadow 1898, Huene 1954, Jaekel 1910, Jaekel 1911, Kuhn 1946, Miguel Chaves et al. 2018, Neenan et al. 2013, Nopcsa 1928, O'Keefe 2001, Osborn 1903, Osborn 1903, Osborn 1904, Perrier 1928, Pinna and Nosotti 1989, Rieppel 1995, Rieppel 2000, Rieppel 2000, Roxo 1937, Sepkoski 2002, Swinton 1934 and Zittel 1890
Sister taxa: Atopodentatus, Cercidopleura, Dicranopleura, Eosauropterygia, Eusauropterygia, Ischyrosaurus, Microleptosaurus, Nanchangosauroidea, Nothosauria, Nothosauriformes, Pistosauria, Placodontiformes, Plesiosauria, Simosauria
Subtaxa: Chelyposuchus Cyamodontidae Cyamodontoidea Hemilopadidae Henodontida Negevodus Paraplacodontidae Pararcus Placodontida Placodontoidea Priscochelys hegnabrunnensis
Ecology: