This has commonly been cited as having been named by Dollo (1888), since being listed as such in Sereno (1986) with a reference to Hay (1902). But this is incorrect - Dollo named no such group, and Hay was in error, cited presumably without reference back to Dollo (1888) by Sereno (1986). The first known usage of the name is Baur (1891).
Full reference: G. Baur. 1891. Remarks on the reptiles generally called Dinosauria. The American Naturalist 25(293):434-454
Parent taxon: Ornithopoda according to A. O. Fonseca et al. 2024
See also Baur 1891, Benton 1990, Bertozzo et al. 2025, Buchholz 2002, Butler et al. 2008, Cooper 1985, Dieudonné et al. 2020, Escaso et al. 2014, Galton 2007, Galton 2009, Gasulla et al. 2015, Godefroit et al. 1998, Han et al. 2012, Herne et al. 2019, Huang et al. 2026, Ibiricu et al. 2019, Kuhn 1966, Lull 1912, Madzia et al. 2018, Magyar et al. 2026, Matthew 1915, Norman 1989, Norman 2004, Norman 2014, Norman and Sues 2000, Novas et al. 2004, Prieto-Márquez et al. 2019, Russell 1984, Sachs and Hornung 2006, Sancarlo et al. 2025, Sánchez-Hernández et al. 2007, Sereno 1986, Sereno 1997, Sereno 1998, Sereno 1999, Shibata et al. 2011, Shibata et al. 2015, Verdú et al. 2021, Wang et al. 2017, Weishampel and Heinrich 1992, Xu et al. 2018 and Yao et al. 2026
Sister taxa: Anomoepodidae, Bonaparteichnium, Brachypoda, Burianosaurus, Camptosaurichnus, Camptosauropus, Clypeodonta, Dakotasaurus, Dinosauropodes, Dolichopoda, Euornithopoda, Fabrosauria, Gilmoreosaurus arkhangelskyi, Goseongosauripus, Hypsiloichnus, Hypsilophodontidae, Iguanodontipodidae, Iguanodontipodidae, Jiayinosauropus, Kalodontoidea, Laosaurus, Laosaurus celer, Laosaurus minimus, Moyenisauropodidae, Ningxiapus, Ornithopoidea, Othnielia, Phyllodon, Psilotrisauropus, Siluosaurus, Taponichnus, Telosichnus, Tetrapodosauridae, Trachodontoidea, Unespichnium, Walmadanyichnus, Wintonopus
Subtaxa: Albisaurus Albisaurus scutifer Anoplosaurus major Bihariosaurus Camptosauroidea Choyrodon Eucercosaurus Eucercosaurus tanyspondylus Euiguanodontia Fulgurotherium Iguanodon ottingeri Iguanodontoidea Loncosaurus Mantellisaurus Osmakasaurus Planicoxa Rhabdodontomorpha Sphenospondylus Syngonosaurus Syngonosaurus macrocercus Tichosteus Vectisaurus
Ecology: ground dwelling herbivore