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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.
Phylogram and comparison of body size optimization across Allosauroidea. Constructed from the trees recovered by (A) EAC, the present analysis. Silhouettes are to scale according to measurements listed in Table 6.
Caudal vertebrae in Begaraaten ostromi gen. et sp. n. from the ?mid-Maastrichtian Nemegt Formation at Nemegt, Mongolia. A-E. Preserved caudals lst-l3th (A-C) and 1Sth-20th (D, E) in lateral view. F. Anterlor view of 1st preserved caudal with articulated part of spine of preceding caudal. G. Anterior view of I I th preser-ved caudal. Scale bar 2 crn.
Posterior part of left mandible of Bagaraatan ostromi, stereophotographs. in lateral, posterior, dorsal, and medial views. Scale bar - 2 cm.
Comparisons of Victorian ornithopod maxillae in lateral view and schematics, showing dorsalmost extent of the maxillary ramus (indicated by large arrows): (1) Galleonosaurus dorisae n. gen. n sp., holotypic left maxilla (NMV P229196); (2) Atlascopcosaurus loadsi Rich and Rich, 1989, left maxilla (NMV P157390); (3) cast of original holotypic left maxilla of Atlascopcosaurus loadsi (NMV P166409). alv = alveolus; bur = buccal ridge; lpf = lateral palatine flange of maxilla; m#’ = maxillary tooth position (from posterior end) and replacement number; ml = medial lamina of maxilla; mra = maxillary ramus; nvt = neurovascular tract; plp = posterolateral process of maxilla; pmp = posteromedial process of maxilla; sal = supralveolar lamina of maxilla. Scale bars = 10 mm.
Complete specimen of the Laueropterus vitriolus holotype (LF 6268). The holotype specimen seen under natural light. Major elements are labeled. Abbreviations as follows here and in subsequent figures: ca, caudal vertebra; cp, carpal; cv, cervical vertebrae; dv, dorsal vertebra; fe, femur; hu, humerus; mn, mandible; mt, metatarsal; ph, phalanges; pmm, premaxilla-maxilla; pp, prepubis; pt, pteroid; pv, pelvic plate; r, rib; sa, sacrum; sc, scapulocoracoid; sk, skull part; st, sternum; ta, tarsals; ti, tibia; ul, ulna; un, ungual; wpx, wing phalanges; wmc, wing metacarpal. Scale bar = 100 mm.
Chaohusaurus specimen AGM CHS-5, a nearly complete skeleton that is almost as large as AGM I-1. Large scale bars are 10 cm, and short bars 2 cm.
The skull of Janusaurus lundi (PMO 222.654). A: Photo in right lateral view of the skull. B: Right lateral view with interpretation of the individual elements. Abbreviations: a, angular; art, articular; d, dentary; en, external naris; j, jugal; l, lacrimal; mx, maxilla; n, nasal; or, orbit; p, parietal; pmx, premaxilla; po, postorbital; pof, postfrontal; prf, prefrontal; q, quadrate; qj, quadratojugal; sa, surangular; st, supratemporal. Scale = 5 cm.
The holotype and only known specimen of the hauffiopterygian leptonectid, Xiphodracon goldencapensis (ROM VP52596) from Golden Cap, between Charmouth and Seatown, Dorset, UK. The skeleton is exposed in ventrolateral view. The skull has been fully prepared free of matrix whereas most of the skeleton is still in matrix. The left (upper) forefin has been prepared so that it is three-dimensionally preserved and projects upwards. Scale bar represents 20 cm.
Oneirosaurus caballeroi holotype IGMp879524. A, photograph, drawing and interpretative scheme of the specimen without left mandibular ramus, in right lateral view. B, photograph, drawing and interpretative scheme of the specimen without left mandibular ramus, in left lateral view. Gray fill, sediment; pattern fill, broken bone surface; black, empty space. Scale bars: A = 50 mm; C-D = 30 mm. Abbreviations: an, angular; avc, anterior aperture of the vidian canal; bo, basioccipital; bptm, basipterygoid meniscus; bs, basisphenoid; c, coronoid; d, dentary; ec, ectopterygoid; ep, epipterygoid; ex, exoccipital; f, frontal; im, internal auditory meatus; is, interorbital septum; j, jugal; la, lacrimal; m, mandible; mx, maxilla; na, nasal; op, opisthotic-exoccipital; p, parietal; par, prearticular; pl, palatine; pmx, premaxilla; pof, postorbitofrontal; pr, prootic; prf, prefrontal; ps, parasphenoid; pt, pterygoid; pvc, posterior aperture of the vidian canal q; quadrate; rv, right vomer; sa, surangular; scp, sclerotic plate; smx, septomaxilla; so, supraoccipital; sp, splenial; stp, stapes; VII, IX-XII, exit of cranial nerves.
Arambourgiania, Nyctosaurus and Quetzalcoatlus scale
Life restoration of the Triassic ichthyosaur Qianichthyosaurus xingyiensis. References Motani, Ryosuke; Jiang, Da-yong; Tintori, Andrea; Ji, Cheng; Huang, Jian-dong (2017). "Pre- versus post-mass extinction divergence of Mesozoic marine reptiles dictated by time-scale dependence of evolutionary rates". Proceedings of the Royal Society B 284 (1854): 20170241. DOI:10.1098/rspb.2017.0241.
Figure description from paper: "Figure 23: Early and Middle Triassic ichthyopterygian heads possessing longirostry. Simplified outlines of four different Early and Middle Triassic ichthyopterygian heads possessing a long and slender rostrum. Specimens are at the same scale. (A) Utatsusaurus hataii (UHR 30691, Motani, Minoura & Ando, 1998); (B) Grippia longirostris (PMU R445, Motani, 2000); (C) Mixosaurus cornalianus (BES SC 1000, Renesto et al., 2020); (D) Besanosaurus leptorhynchus (PIMUZ T 4847, this paper); (E) Cymbospondylus buchseri (PIMUZ T 4351, Sander, 1989). Scale bar represents 10 cm." References: Bindellini, G.; Wolniewicz, A.S.; Miedema, F.; Scheyer, T.M.; Dal Sasso, C. (2021). "Cranial anatomy of Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996 (Reptilia: Ichthyosauria) from the Middle Triassic Besano Formation of Monte San Giorgio, Italy/Switzerland: Taxonomic and palaeobiological implications". PeerJ 9: e11179. DOI:10.7717/peerj.11179.
Besanosaurus leptorhynchus referred specimen PIMUZ T 4376, preserved on the same slab as a specimen of the smaller Mixosaurus. Scale bar represents 50 cm (1.6 ft). Figure 3C of Bindellini et al. (2021). References: Bindellini, G.; Wolniewicz, A.S.; Miedema, F.; Scheyer, T.M.; Dal Sasso, C. (2021). "Cranial anatomy of Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996 (Reptilia: Ichthyosauria) from the Middle Triassic Besano Formation of Monte San Giorgio, Italy/Switzerland: Taxonomic and palaeobiological implications". PeerJ 9: e11179. DOI:10.7717/peerj.11179.