Find research datasets worth reusing

opencc-by-4.0Nov 2023View details →

Fig. 1 in Enamel microstructure and dental histology in a heterodontosaurid dinosaur: Heterodontosaurus tucki

Fig. 1. Heterodontosaurid dinosaur Heterodontosaurus tucki Crompton and Charig, 1962 (BP/1/9007), from Lower Jurassic upper Elliot Massospondylus Assemblage Zone of South Africa. Left partial maxillary tooth row in lingual view; preserves partial crowns with wear facets. Blue plane indicates location of histological transverse sections from the middle of the tooth row.

Fig. 10 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 10. Comparative morphology of lower molars of Hadrocodium and Morganucodon. A. The morganucodontan Morganucodon oehleri Rigney, 1963, from the Lower Lufeng Formation, Lower Jurassic of China. BMNH 2858, ultimate lower molar (right m4) lingual (A1) and oblique occlusal (A2, stereopairs) views. B. The morganucodontan Morganucodon watsoni Kühne, 1949, from the Lower Jurassic fissure fills of Wales. UMZC Eo.CR1, ultimate molar (m4); lingual view (B1) (Jäger et al. 2019, image courtesy of Kai Jäger), lingual (B2) and occlusal (B3) views (Gill et al. 2014, images courtesy of Pamela Gill). C. The mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001, from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. Holotype, IVPP 8275, right m1 and m2 in occlusal (C1, stereopairs) and lingual (C2) views.

Fig. 9 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 9. Comparative morphology of incisors and canine among mammaliaforms. A, B. The morganucodontan Morganucodon oehleri Rigney, 1963, from the Lower Lufeng Formation, Lower Jurassic of China. A. CUP-FMNH 2320, type specimen. B. BMNH 2858, whole tooth and oblique-horizontal slice to visualize the single root canal. C. The mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China; C1, upper incisors and canine; C2, lower incisors and canine. D. The docodontan Haldanodon exspectatus Kühne and Krusat, 1972 (Gui-Mam 41/75) from the Guimarota Coal Mine, Upper Jurassic of Portugal (Ruf et al. 2013; Huttenlocker et al. 2018). E. The docodontan Docofossor brachydactylus Luo, Meng, Ji, Liu, Zhang, and Neander, 2015b (BMNH 131735) from the Tiaojishan Formation, Upper Jurassic of China (Luo et al. 2015b). F. The docodontan Agilodocodon scansorius Meng, Ji, Zhang, Liu, Grossnickle, and Luo, 2015 (BMNH 00138) from the Tiaojishan Formation, Upper Jurassic of China (Meng et al. 2015b); F1, left upper incisors and canine in lingual view; F2, left lower incisors and canine (flipped). Hadrocodium wui is similar to Haldanodon exspectatus and Docofossor brachydactylus in the upper canine with fully divided roots, and to all docodonts in bilaterally compressed lower canine with partially divided (grooved) root(s) and the separated root canals inside the root(s). Hadrocodium wui is also similar to Kuehneotherium praecursoris is also similar to Kuehneotherium in this feature (Gill 2004). Hadrocodium wui differs from Morganucodon oehleri and Sinoconodon rigneyi both of which are characterized by single-rooted and tubular upper and lower canines.

Fig. 7 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 7. CT rendering of mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. A. Left upper teeth (as preserved and virtually extracted from the upper jaws): incomplete incisors, canine, incomplete premolars and two molars in lingual (A1, stereopairs) and labial (A2, stereopairs) views. Left dentition has five incisor positions: two broken incisors, plus three additional incisors represented by alveoli visible on the fossil skull (but not visualized in teeth). Of the three premolars, P1 is not preserved, but P1 position is represented by a plugged alveolus on right side (not visualized here). P2 is preserved on right side, but is lost and represented only by empty alveoli on the left. P3 is intact on both sides. B. Right upper teeth: five upper incisors (I1 and I5 broken), canine, two premolars, two molars in lingual (B1, stereopairs) and labial (B2, stereopairs) views.

Fig. 8 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 8. CT rendering of mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. A. Left lower teeth (as preserved and virtually extracted from mandible): incisors, canine, incomplete premolars molars in labial (A1, stereopairs) and lingual (A2, stereopairs) views. The first premolar (p1) was shed and the vestige of its former alveoli recognizable on right mandible; penultimate premolar (p2) crown broken; ultimate p3 intact. B. Right lower teeth extracted by CT visualization, in labial (B1, stereopairs) and lingual (B2, stereopairs) views.

Fig. 5 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 5. Comparative morphology of mandibular canals and tooth alveoli in cross sections. A. The mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China; transverse section of mandible through anterior root of p3 (A1): the main cusp of a tall p3 occludes into its maxillary pit on the palate, and the upper P3 is more lingually inclined than the lower p3; transverse section through anterior root of m1 (A2): the mandibular canal is lateral to the root alveoli of the postcanines; the upper M1 is more inclined lingually than the lower m1; the main cusp of lower m1 occludes into its pit on the palate; the asterisk indicates that the labial alveolar margin is lower on the lingual alveolar margin at the point of the arrow. B. The morganucodontan Morganucodon oehleri Rigney, 1963, (BMNH 2858) from the Lower Lufeng Formation, Lower Jurassic of China; cross section through the anterior root of m2: oval outline with long diameter at 0.25 mm, and short diameter at 0.15 mm; mandibular canal is lateral to the side of roots. C, D. The docodontan Docodon victor Schultz, Bhullar, and Luo, 2019 (as revised by Schultz et al. 2019) from the Morrison Formation, Upper Jurassic of Wyoming, USA. C. YPM 11826, cross section through a root alveolus of m5; mandibular canal cross section in oval outline with the long diameter at 0.8 mm and short diameter at 0.6 mm. D. YPM 11823, mandibular canal cross section through anterior root of m5; circular outline diameter 0.6 mm. The mandibular canal is ventro-lateral to the apices of roots in docodontans. E. The eutriconodontan Juchilestes liaoningensis Gao, Wilson, Luo, Maga, Meng, and Wang, 2009 (DMNH 2607) from the Yixian Formation, Lower Cretaceous of China, as a representative for root canal pattern for crown mammals, in which the mandibular canal is ventral to the root apices.

Fig. 6 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 6. Composite reconstruction of full dentition of Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. A. Left upper teeth (as preserved) in labial view (CT visualization). B. Lower teeth (as preserved) in lingual view. C. Composite reconstruction of upper and lower teeth (left labial view). D. Occlusal relationship of cusps between lower m1–m2 and upper P3–M1– M2 (revised from Luo et al 2001: fig. 1; cusp designation following Crompton and Jenkins 1968 and Crompton 1974).

Fig. 3 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 3. CT rendering of the mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. A. Left mandible in medial view (stereopairs). B. Right mandible in tilted dorsal view (B1, stereopairs), p1 is lost but the p1 position is indicated by plugged alveoli; arrow indicates the retro-molar space; and medial view (B2, stereopairs).

Fig. 2 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 2. CT rendering of the mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. A. Right mandible in lateral view (stereopairs); solid triangle indicates the retro-molar space. B. Left mandible in lateral B1, stereopairs) and ventral (B2, stereopairs) views.

Fig. 11 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 11. Comparison of the mandible of Hadrocodium with the mandibular growth stages of Morganucodon and Docodon. A. The mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China (arrow indicates the retro-molar space and feature of adult). B, C. Mandibular growth stages of the morganucodontan Morganucodon watsoni Kühne, 1949 (= "Eozostrodon parvus") from the Lower Jurassic fissure fills of Wales (Parrington 1971); adult (B) and the oldest-known adult (C) (respectively specimens D60 and D120 in Parrington 1971: fig. 3). D–F. Mandibular growth stages of the docodontan Docodon victor Schultz, Bhullar, and Luo, 2019, from the Morrison Formation, Upper Jurassic of Wyoming, USA. D. YPM 23748, juvenile. E. YPM 11823, adult. F. YPM 11826, the oldest-known adult. In H. wui, the ultimate molar is positioned in front of the coronoid process base. This is an adult feature well documented in the successively older (or the oldest-known) adult individuals in the growth series of other mammaliaforms. Morganucodon watsoni shows such a growth pattern: a positional shift of the ultimate molar (m4) anteriorly to the base of coronoid process in successively older individuals; the ultimate molar has a single alveolus for its fused or confluent root(s) in most cases (Parrington 1971; Pamela Gill, personal communication 2021). Docodon victor shows a similar growth pattern of a shift of the coronoid process relative to the last molar(s) of the toothrow. The youngest-available individual D. victor (YMP23748) shows the last molar (m5) is medial to the coronoid process. In the adult (YPM11823) the last molar (m7) is shifted more anteriorly. In the oldest-available individual (YPM11826), the ultimate molar (m8) is shifted to the anterior, as the coronoid process is shifted posteriorly relative to the toothrow (Schultz et al. 2019). The placement of the ultimate molar with a retro-molar space anterior to the base of the coronoid in the oldest-available adult specimen of D. victor is similar to that of H. wui. D–F, stylistic illustrations based on CT visualizations by Schultz et al. (2019).

Fig. 4 in Reexamination of the mandibular and dental morphology of the Early Jurassic mammaliaform Hadrocodium wui

Fig. 4. CT rendering of the mammaliaform Hadrocodium wui Luo, Crompton, and Sun, 2001 (holotype, IVPP 8275) from the Lower Lufeng Formation, Lower Jurassic of Yunnan, China. A. Mandibles and upper teeth (as preserved) in ventral view. B. Mandibles in association with upper teeth in dorsal view. The upper teeth are more inclined (as preserved) and are oblique to the lower teeth. Post-mortem distortion caused the upper postcanines to shift relative to lower teeth, by half a cusp length.

Fig. 5 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 5. Isolated tooth (Morphotype 2) from the Cerro de los Leones locality, Albian, Lower Cretaceous, Picún Leufú, Argentina. MCF-PVPH-880-1 in labial (A1, A2), lingual (A3, A4), distal (A5, A6), and mesial (A7, A8) views. The basal cross section (A9, A10) is visible due to the natural breaking of the crown.

Fig. 6 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 6. Isolated tooth (Morphotype 3) from the Cretaceous Cerro de los Leones locality, Picún Leufú, Argentina. MCF-PVPH-879-2 in labial (A1, A2), lingual (A3, A4), distal (A5, A6), and mesial (A7, A8) views. The basal cross section (A9, A10) is visible due to the natural breaking of the crown.

Fig. 7 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 7. Tooth morphotype distribution in ornithocheiriform upper and lower jaw (A) with associated crown size and cross-section variation (B). Example based on Anhanguera piscator (Kellner and Tomida 2000).

Fig. 4 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 4. Isolated tooth (Morphotype 1) from the Cerro de los Leones locality, Albian, Lower Cretaceous, Picún Leufú, Argentina. MCF-PVPH-879-8 in labial (A1, A2), lingual (A3, A4), mesial (A5, A6), and distal (A7, A8) views. The basal cross section (A9, A10) is visible due to the natural breaking of the crown.

Fig. 8 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 8. Life reconstruction of the Cerro de los Leones pterosaur, displaying the morphological diversity of its dentition based on the observed distribution of the morphotypes. Illustration by Alessio Ciaffi.

Fig. 3 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 3. Isolated pterosaur teeth from the Cerro de los Leones locality, Albian, Lower Cretaceous, Picún Leufú, Argentina. Morphotype 1 (H, J, L, N), Morphotype 2 (A, C, M, P, Q, R, S), and Morphotype 3 (B, D, E, G, I, K, O, T). A. MCF-PVPH-739-2. B. MCF-PVPH-741. C. MCF-PVPH-743. D. MCFPVPH-875. E. MCF-PVPH-879-1. F. MCF-PVPH-879-2. G. MCF-PVPH-879-3. H. MCF-PVPH-879-4. I. MCF-PVPH-879-5. J. MCFPVPH-879-6. K. MCF-PVPH-879-7. L. MCF-PVPH-879-8. M. MCF-PVPH-879-9. N. MCF-PVPH-879-10. O. MCF-PVPH-879-11. P. MCFPVPH-880-1. Q. MCFPVPH-880-2. R. MCF-PVPH-880-3. S. MCF-PVPH-880-4. T. MCF-PVPH-880-5. In labial (A–G, I, K, O–Q, S, T), lingual (H, M, N, R), and mesial (J, L) views.

Fig. 2 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 2. Stratigraphic column of the Cullín Grande Member (Lohan Cura Formation), Albian, Lower Cretaceous, Cerro de Los Leones, Patagonia, Argentina. Architectural element codes follow Miall 1996: CS, crevasse channel; FF, floodplain fines; LA, lateral accretion; LS, laminated sand sheets; LV, levee; SB, sandy bedforms. Modified from Martinelli et al. 2007 with silhouettes from www.phylopic.org: pterosaur (Anhanguera santanae) silhouette credit of Leon P.A.M. Claessens, Patrick M. O'Connor, David M. Unwin; sauropod (Dreadnoughtus schrani) silhouette by Scott Hartman; theropod Giganotosaurus carolinii) silhouette by Tasman Dixon; crocodile silhouette by B. Kimmel. Anhanguera santanae and Dreadnoughtus schani silhouettes license: https://creativecommons.org/licenses/by-sa/3.0/.

Fig. 1 in Pterosaur teeth from the Southern Neuquén Basin (Patagonia, Argentina): New insights on the reconstruction of ornithocheiriform dental anatomy

Fig. 1. Geographic position of Cerro de los Leones in the Neuquén Basin. A. Map of the Neuquén Basin, showing position of the studied area (asterisk); white dashed line indicates the boundary of the Neuquén Basin; yellow line indicates the boundary between Chile and Argentina. Satellite views of the Cerro de los Leones area showing relation to Picún Leufú (B) and locations (asterisks) of provenance of vertebrate fossils (images from Google Earth).