Ornithischia (Seeley, 1888)

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), Zoological Journal of the Linnean Society 196 (4), pp. 1273-1309 : 1286

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 ).

Figures

Figure 5. Third analysis forcing Chilesaurus diegosuarezi in Theropoda. Abbreviations: Aphan, Aphanosauria; Herrer, Herrerasauridae. Silhouettes are based on artwork by Márcio L. Castro, Gabriel Lio, Rodrigo T. Müller, Maurício S. Garcia, John Sibbick and Douglas M. Heman.

Figure 6. Strict consensus treefrom the unconstrained analysis depicting nodenumbers mentioned in thetext and bootstrap values equal to or higher than 40%. Node numbers: 1, Dinosauria; 2, Saurischia; 3, Ornithischia; 4, Sulcimentisauria; 5, Parapredentata; 6, Unnamed; 7, Prionodontia; 8, Thyreophora; 9, Neornithischia; 10, Heterodontosauridae. Saltopus elginensis was removed from the strict consensus tree after an iterPCR analysis (Pol & Escapa, 2009). Silhouettes based on the artwork by Márcio L. Castro, Gabriel Lio, Rodrigo T. Müller, Maurício S. Garcia and John Sibbick.

Figure 7. Body plan evolution within Ornithischia and character states with phylogenetic importance for the present hypothesis. A, skeletal reconstruction of Silesaurus opolensis, a parapredentatan (stem lineage) ornithischian (after Dzik, 2003). B, skeletal reconstruction of Laquintasaura venezuelae, a parapredentatan ornithischian (after Barrett et al., 2014). C, skeletal reconstruction of Eocursor parvus, a prionodontian ornithischian (after Butler et al., 2010). D, left dentary of Kwanasaurus williamparkeri (DMNH EPV.63136) in lateral view (modified from Martz & Small, 2019). E, left ectopterygoid of Asilisaurus kongwe (NMT RB159) in posterior (modified from Nesbitt et al., 2019). F, posterior portion of the right hemimandible of Asilisaurus kongwe (NMT RB159) in lateral (modified from Nesbitt et al., 2019). G, partial left dentary of Asilisaurus kongwe (NMT RB159) in occlusal view (modified from Nesbitt et al., 2019). H, left dentary of Kwanasaurus williamparkeri (DMNH EPV.63136) in medial view (modified from Martz & Small, 2019). I, isolated tooth of Kwanasaurus williamparkeri (DMNH EPV.63843) in labial view (modified from Martz & Small, 2019). J, proximal portion of the right femur of Sacisaurus agudoensis (MCN PV100014) in caudomedial view. K, right maxilla of Echinodon becklesii (NHMUK OR48211) in lateral view (modified from Sereno, 2012). L, right tibia of Eocursor parvus (SAM-PK-K8025) in proximal view. M, left pelvic elements of Heterodontosaurus tucki (SAM-PK-K1332) in lateral view. N, skull of Heterodontosaurus tucki (SAM-PK-K1332) in right lateral view. O, cervical 6 and 7 of Heterodontosaurus tucki (SAM-PK-K1332) in left lateral view. P, proximal portion of the right tibia of Eocursor parvus (SAM-PK-K8025) in lateral view. Q, left ischium of Lesothosaurus diagnosticus (SAM-PK-K1105) in medial view (modified from Baron et al., 2017a). R, proximal portion of the left femur of Lesothosaurus diagnosticus (BP/1/6582) in lateral view. Elements are not to scale.