Saurischia Seeley 1887 [Gauthier 1986], nom. cl. inval. see Clade Saurischia Seeley 1888 [Gauthier, Langer, Novas, Bittencourt & Ezcurra 2020]
   †Sauropoda Marsh 1878 [Salgado et al. 1997]
     †Neosauropoda Bonaparte 1986 [Wilson & Sereno 1998]
       †Diplodocoidea Upchurch 1995 [Wilson & Sereno 1998] see Superfamily Diplodocoidea Marsh, 1884
         1.1.1.1 †Flagellicaudata Harris & Dodson 2004
         1.1.1.2 †Rebbachisauridae Bonaparte 1997 [Wilson 2004] see Family Rebbachisauridae Bonaparte, 1997
         1.1.2 Genus †Amphicoelias Cope, 1877
         1.2 Genus †Amazonsaurus Carvalho, Avilla & Salgado, 2003
         2 Genus †Haplocanthosaurus Hatcher, 1903