Advertisement

The Science of Nature

, 105:41 | Cite as

Heterodonty and double occlusion in Manidens condorensis: a unique adaptation in an Early Jurassic ornithischian improving masticatory efficiency

  • Marcos G. Becerra
  • Diego Pol
  • Gertrud E. Rössner
  • Oliver W. M. Rauhut
Short Communication

Abstract

New materials of the ornithischian dinosaur Manidens condorensis highlight a strong heterodonty between the upper and lower dentitions and reveal a novel occlusion type previously unreported in herbivorous dinosaurs. The diamond-shaped maxillary teeth have prominent cingular entolophs in a V- to Z-shaped configuration that are absent in dentary teeth. These cingular entolophs bear denticles and serrations with vertical wear that is coplanar with the apical wear facets, supporting their involvement in chewing. The separated apical and basal wear in dentary teeth is consistent with the apical and cingular wear in maxillary teeth, indicating an alternate occlusion, an orthal jaw motion, and shearing interactions between marginal and cingular edges in a double occlusion. Measurements of the length and wear area along the marginal and cingular edges indicate that the latter are functionally equivalent to adding eight teeth to a maxillary toothrow of ten, almost doubling the lengths of cutting edges and the degree of intraoral processing, while maintaining a plesiomorphic skull anatomy, an adaptation to herbivory unique in Ornithischia.

Keywords

Manidens condorensis Ornithischia Maxillary dentition Heterodonty Jaw mechanics 

Notes

Acknowledgements

Dr. Y. Herrera (UNLP), the institution and staff from the Staatliche Naturwissenschaftliche Sammlungen Bayerns (Munich), and the reviewers are thanked.

Funding information

The Deutscher Akademischer Austauschdienst (DAAD) financed the travel for M.G.B. to Germany (ID 57130097); fieldwork and research were supported by Agencia Nacional de Promoción Científica y Técnica to D.P. (ANPCyT, PICT 1288 and 0808), Deutsche Forschungsgemeinschaft to O.W.M.R. (DFG, RA1012/9-1), and National Science Fundation to Dr. G. Rougier (NSF, DEB 0946430 and DEB 1068089).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

114_2018_1569_MOESM1_ESM.pdf (57.1 mb)
ESM 1 (PDF 58435 kb)
114_2018_1569_MOESM2_ESM.pdf (69 kb)
ESM 2 (PDF 68 kb)
114_2018_1569_MOESM3_ESM.pdf (31 kb)
ESM 3 (PDF 30 kb)

References

  1. Barrett PM, McGowan AJ, Page V (2009) Dinosaur diversity and the rock record. Proc R Soc Lond B 276:2667–2674CrossRefGoogle Scholar
  2. Becerra MG, Pol D, Marsicano CA, Rauhut OWM (2014) The dentition of Manidens condorensis (Ornithischia; Heterodontosauridae) from the Jurassic Cañadón Asfalto Formation of Patagonia: morphology, heterodonty and the use of statistical methods for identifying isolated teeth. Hist Biol 26:480–492CrossRefGoogle Scholar
  3. Bell PR, Snively E, Shychoski L (2009) A comparison of the jaw mechanics in hadrosaurid and ceratopsid dinosaurs using finite element analysis. Anat Rec 292:1338–1351CrossRefGoogle Scholar
  4. Butler RJ, Upchurch P, Norman DB (2008) The phylogeny of the ornithischian dinosaurs. J Syst Palaeontol 6:1–40CrossRefGoogle Scholar
  5. Cuthbertson RS, Tirabasso A, Rybczynski N, Holmes RB (2012) Kinetic limitations of intracranial joints in Brachylophosaurus canadensis and Edmontosaurus regalis (Dinosauria: Hadrosauridae), and their implications for the chewing mechanics of hadrosaurids. Anat Rec 295:968–979CrossRefGoogle Scholar
  6. Erickson GM, Krick BA, Hamilton M, Bourne GR, Norell MA, Lilleodden E, Sawyer WG (2012) Complex dental structure and wear biomechanics in hadrosaurid dinosaurs. Science 338:98–101CrossRefPubMedGoogle Scholar
  7. Fedorov A, Beichel R, Kalpathy-Cramer J, Finet J, Fillion-Robin JC, Pujol S, Bauer C, Jennings D, Fennessy F, Sonka M, Buatti J (2012) 3D Slicer as an image computing platform for the Quantitative Imaging Network. Magn Reson Imaging 30:1323–1341CrossRefPubMedPubMedCentralGoogle Scholar
  8. Irmis RB, Parker WG, Nesbitt SJ, Liu J (2007) Early ornithischian dinosaurs: the Triassic record. Hist Biol 19:3–22CrossRefGoogle Scholar
  9. MacLaren JA, Anderson PS, Barrett PM, Rayfield EJ (2017) Herbivorous dinosaur jaw disparity and its relationship to extrinsic evolutionary drivers. Paleobiology 43:15–33CrossRefPubMedGoogle Scholar
  10. Nabavizadeh A (2016) Evolutionary trends in the jaw adductor mechanics of ornithischian dinosaurs. Anat Rec 299:271–294CrossRefGoogle Scholar
  11. Norman DB, Crompton AW, Butler RJ, Porro LB, Charig AJ (2011) The Lower Jurassic ornithischian dinosaur Heterodontosaurus tucki Crompton & Charig, 1962: cranial anatomy, functional morphology, taxonomy, and relationships. Zool J Linn Soc-Lond 163:182–276Google Scholar
  12. Ösi A, Barrett PM, Földes T, Tokai R (2014) Wear pattern, dental function, and jaw mechanism in the Late Cretaceous ankylosaur Hungarosaurus. Anat Rec 297:1165–1180CrossRefGoogle Scholar
  13. Pol D, Rauhut OWM, Becerra MG (2011) A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids. Naturwissenschaften 98:369–379CrossRefPubMedGoogle Scholar
  14. Schneider CA, Rasband WS, Eliceiri KW (2012) NIH image to ImageJ: 25 years of image analysis. Nat Methods 9:671–675CrossRefPubMedPubMedCentralGoogle Scholar
  15. Sereno PC (1997) The origin and evolution of dinosaurs. Annu Rev Earth Pl Sc 25:435–489CrossRefGoogle Scholar
  16. Sereno PC (2012) Taxonomy, morphology, masticatory function and phylogeny of heterodontosaurid dinosaurs. ZooKeys 226:1–225CrossRefGoogle Scholar
  17. Sereno PC, Xijin Z, Lin T (2010) A new psittacosaur from Inner Mongolia and the parrot-like structure and function of the psittacosaur skull. Proc R Soc Lond B 277:199–209CrossRefGoogle Scholar
  18. Strickson E, Prieto-Márquez A, Benton MJ, Stubbs TL (2016) Dynamics of dental evolution in ornithopod dinosaurs. Sci Rep-UK 6:28904CrossRefGoogle Scholar
  19. Weishampel DB, Dodson P, Osmólska H (2004) The Dinosauria, 2nd edn. University of California Press, BerkeleyCrossRefGoogle Scholar
  20. Williams VS, Barrett PM, Purnell MA (2009) Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding. P Natl Acad Sci USA 106:11194–11199CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.CONICET - Museo Paleontológico Egidio FeruglioTrelewArgentina
  2. 2.SNSB, Bayerische Staatssammlung für Paläontologie und Geologie, and Department for Earth and Environmental Sciences and GeoBioCenterLMU MünchenMunichGermany

Personalised recommendations