Ornithischia

Figure 1. Evolution of macroecological traits in Dinosauria. Large scale event in dinosaur evolution (a); the origin of dinosaurs (star), hyperthermals (volcano), the earliest fossil Avialae (bird), the earliest fossil angiosperm (flower), the Cretaceous/Palaeogene mass extinction (asteroid). Phylogeny of dinosaurs (b) redrawn from Sereno and adapted to the current consensus and upon which an ancestral state reconstruction of temperature niche (mean annual temperature) after Chiarenza et al. is plotted; Mesozoic palaeogeographies (c) for Triassic (T), Jurassic (J) and Cretaceous (K). Silhouette colours symbolize body mass for each of the taxa represented; information on dietary habits are plotted after Barrett and Zanno & Makovicky; numbers represent clades discussed through this study: 1, Ornithischia; 2, Thyreophora; 3, Ornithopoda; 4, Hadrosauroidea; 5, Marginocephalia; 6, Ceratopsia; 7, Saurischia; 8, Sauropodomorpha; 9, Sauropoda; 10, Theropoda; 11, Ceratosauria; 12, Tetanurae; 13, Coelurosauria; 14, Maniraptoriformes; 15, Maniraptora; 16, Deinonychosauria; 17, Avialae; 18, Ornithothoraces. Palaeogeographies modified from original plots via R package ‘mapast’ using plate models by Scotese.

Cladogram of amniotes. Based on File:Cladogram Amniota A.jpg

Cladogram of the former "Reptilia" (red)

Ornithischian dinosaur Stenopelix valdensis Meyer, 1857, holotype (GZG 741/2, formerly GPI Gö 741−2), from the Obernkirchen Sandstone (Early Cretaceous: Berriasian), near Bückeburg, Niedersachsen, Germany. A. Large sandstone slab. B. Interpretative outline drawing of large latex cast (prepared from large sandstone slab), showing majority of postcranial skeleton in dorsal view. C. Small sandstone slab. D. Interpretative outline drawing of small la− tex cast (prepared from small sandstone slab), showing sacrum and caudals, pelvic region and partial hindlimbs in ventral view. For clarity elements in and around the sacral region have not been labelled—these areas are shown in greater detail in Fig. 3. Roman numerals II–IV correspond to respective digits. Abbreviations: mt, metatarsals; f, femur; ?, unidentified element.

Diagram featuring the holotype skull (ZPAL MgD-I/105) of Tylocephale gilmorei in left lateral view. Scale bar equals 5 cm (50 mm). Based on Maryańska & Osmólska, 1974,[1] and Sullivan, 2006.[2] References ↑ (1974). "Pachycephalosauria, a new suborder of ornithischian dinosaurs". Palaeontologica Polonica (30): 45−102. ↑ (2006). "A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia)". New Mexico Museum of Natural History and Science Bulletin (35): 347–365.

Life restoration of Morrosaurus antarcticus based on fossil images. Integument based on small, bipedal ornithischians like Kulindadromeus.

Left femur of cf. Iguanodontidae gen. et sp. indet. (Ornithischia, Ornithopoda), IGP MZHLZ/2003/1, in posterior (A), lateral (B), medial (C), ante− rior (D), and distal (F) views, with transverse cross−section through the femoral shaft (E).