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Jaw roll and jaw yaw in early mammals

Matters Arising to this article was published on 17 June 2020

The Original Article was published on 13 February 2019

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Fig. 1: Tribosphenic molar evolution and the lack of a grinding surface in pre-therian molars.
Fig. 2: Evolutionary changes to the mammalian jaw that contradict the hypothesis that jaw roll grinding evolved in early cladotherians.

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No new data were generated in this study.


  1. 1.

    Bhullar, B. S. et al. Rolling of the jaw is essential for mammalian chewing and tribosphenic molar function. Nature 566, 528–532 (2019).

    ADS  CAS  Article  Google Scholar 

  2. 2.

    Crompton, A. W. (1971) The origin of the tribosphenic molar. In Early Mammals: 2. Symposium Arranged by the Linnean Society (eds Kermack, D. M., & Kermack, K. A.) 65–87 (Linnean Society of London, 1971).

  3. 3.

    Kielan-Jaworowska, Z., Cifelli, R. L. & Luo, Z. X. Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure (Columbia Univ. Press, 2004).

  4. 4.

    Davis, B. M. Evolution of the tribosphenic molar pattern in early mammals, with comments on the “dual-origin” hypothesis. J. Mamm. Evol. 18, 227–244 (2011).

    Article  Google Scholar 

  5. 5.

    Schultz, J. A. & Martin, T. Function of pretribosphenic and tribosphenic mammalian molars inferred from 3D animation. Naturwissenschaften 101, 771–781 (2014).

    ADS  CAS  Article  Google Scholar 

  6. 6.

    Grossnickle, D. M. The evolutionary origin of jaw yaw in mammals. Sci. Rep. 7, 45094 (2017).

    ADS  CAS  Article  Google Scholar 

  7. 7.

    Clemens, W. A. Origin and early evolution of marsupials. Evolution 22, 1–18 (1968).

    Article  Google Scholar 

  8. 8.

    Kay, R. F. & Hiiemae, K. M. Jaw movement and tooth use in recent and fossil primates. Am. J. Phys. Anthropol. 40, 227–256 (1974).

    CAS  Article  Google Scholar 

  9. 9.

    Radinsky, L. Patterns in the evolution of ungulate jaw shape. Am. Zool. 25, 303–314 (1985).

    Article  Google Scholar 

  10. 10.

    Turnbull, W. D. Mammalian masticatory apparatus. Fieldiana Geol. 18, 149–356 (1970).

    Google Scholar 

  11. 11.

    Crompton, A. W., Owerkowicz, T. & Skinner, J. Masticatory motor pattern in the koala (Phascolarctos cinereus): a comparison of jaw movements in marsupial and placental herbivores. J. Exp. Zool. A Ecol. Integrat. Physiol. 313, 564–578 (2010).

    Article  Google Scholar 

  12. 12.

    Grossnickle, D. M. Feeding ecology has a stronger evolutionary influence on functional morphology than on body mass in mammals. Evolution 74, 610–628 (2020).

    Article  Google Scholar 

  13. 13.

    Maynard, S. J. & Savage, R. J. G. The mechanics of mammalian jaws. Sch. Sci. Rev. 40, 289–301 (1959).

    Google Scholar 

  14. 14.

    Lieberman, D. E. & Crompton, A. W. Why fuse the mandibular symphysis? A comparative analysis. Am. J. Phys. Anthropol. 112, 517–540 (2000).

    CAS  Article  Google Scholar 

  15. 15.

    Herring, S. W. TMJ anatomy and animal models. J. Musculoskelet. Neuronal Interact. 3, 391–394 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

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D.M.G. performed all work in this study.

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Correspondence to David M. Grossnickle.

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Grossnickle, D.M. Jaw roll and jaw yaw in early mammals. Nature 582, E6–E8 (2020).

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