Ornithischia (Fig. 6: stem/branch 3) Definition adopted: The most inclusive clade that includes Iguanodon bernissartensis but neither Megalosaurus bucklandii nor Diplodocus carnegii (after Baron et al., 2017a). Characters in support: Horizontal or only gently arched premaxillary palate (Char. 17: 0 → 1); strongly curved and hook-shaped jugal process of the ectopterygoid (Char. 57: 0 → 1; Fig. 5E); ventrally inclined dorsal surface of the rostrum of the dentary (Char. 74: 0 → 1); retroarticular is slightly upturned at its distal end (Char. 82: 0 → 1; Fig. 7F); premaxilla with four teeth (Char. 84: 0 → 1); teeth ankylosed into the alveoli (Char. 100: 0 → 1; Fig. 7G); and medial articular facet of the proximal portion of the femur is straight in caudomedial view (Char. 213: 0 → 1; Fig. 7J).

Published as part of Norman, David B, Baron, Matthew G, Garcia, Mauricio S & Müller, Rodrigo Temp, 2022, Taxonomic, palaeobiological and evolutionary implications of a phylogenetic hypothesis for Ornithischia (Archosauria: Dinosauria), pp. 1273-1309 in Zoological Journal of the Linnean Society 196 (4) on page 1286, DOI: 10.1093/zoolinnean/zlac062, http://zenodo.org/record/7381299