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Large Mesozoic mammals fed on young dinosaurs

Abstract

Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs1,2,3,4,5. The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China6,7. An adult individual of R. robustus was the size of a Virginia opossum. Here we report a new species of the genus, represented by a skeleton with most of the skull and postcranium preserved in articulation. The new species is 50% larger than R. robustus in skull length. In addition, stomach contents associated with a skeleton of R. robustus reveal remains of a juvenile Psittacosaurus, a ceratopsian dinosaur. Our discoveries constitute the first direct evidence that some triconodont mammals were carnivorous and fed on small vertebrates, including young dinosaurs, and also show that Mesozoic mammals had a much greater range of body sizes than previously known. We suggest that Mesozoic mammals occupied diverse niches and that some large mammals probably competed with dinosaurs for food and territory.

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Figure 1: Holotype of Repenomamus giganticus (IVPP V14155).
Figure 2
Figure 3: The postcranial skeleton of R. robustus (IVPP V13605).
Figure 4: Relationship between basal mammals with attached lower jaws to show their relative sizes (adopted from ref. 7)

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References

  1. Bakker, R. T. Dinosaur physiology and the origin of mammals. Evolution 25, 636–658 (1971)

    Article  Google Scholar 

  2. Hopson, J. A. Endothermy, small size and the origin of mammalian reproduction. Am. Nat. 107, 446–452 (1973)

    Article  Google Scholar 

  3. Jerison, H. J. Evolution of the Brain and Intelligence (Academic, New York, 1973)

    Google Scholar 

  4. Crompton, A. W., Taylor, C. R. & Jagger, J. A. Evolution of homeothermy in mammals. Nature 272, 333–336 (1978)

    Article  ADS  CAS  Google Scholar 

  5. Lillegraven, J. A. in Mesozoic Mammals: The First Two-thirds of Mammalian History (eds Lillegraven, J. A., Kielan-Jaworowska, Z. & Clemens, W. A.) 1–6 (Univ. California Press, Berkeley, 1979)

    Google Scholar 

  6. Li, J.-L., Wang, Y., Wang, Y.-Q. & Li, C.-K. A new family of primitive mammal from the Mesozoic of western Liaoning, China [in Chinese]. Chin. Sci. Bull. 45, 2545–2549 (2000)

    Google Scholar 

  7. Wang, Y.-Q., Hu, Y.-M., Meng, J. & Li, C.-K. An ossified Meckel's cartilage in two Cretaceous mammals and origin of the mammalian middle ear. Science 294, 357–361 (2001)

    Article  ADS  CAS  Google Scholar 

  8. Zhou, Z.-H., Barrett, P. M. & Hilton, J. An exceptionally preserved Lower Cretaceous ecosystem. Nature 421, 807–814 (2003)

    Article  ADS  CAS  Google Scholar 

  9. Li, C.-K., Wang, Y.-Q., Hu, Y.-M. & Meng, J. A new species of Gobiconodon from the Jehol Biota and its implication to the age of the fauna. Chin. Sci. Bull. 48, 177–182 (2003)

    CAS  Google Scholar 

  10. Wang, S.-S., Wang, Y.-Q., Hu, H.-G. & Li, H.-M. The existing time of Sihetun vertebrate in western Liaoning, China—Evidence from U-Pb dating of zircon [in Chinese with English abstract]. Chin. Sci. Bull. 46, 779–782 (2001)

    Article  CAS  Google Scholar 

  11. Xu, X. & Wang, X.-L. A new dromaeosaur (Dinosauria: Theropoda) from the Early Cretaceous Yixian Formation of western Liaoning. Vert. PalAsiat. 42, 111–119 (2004)

    Google Scholar 

  12. Nowak, R. M. Walker's Mammals of the World 6th edn (Johns Hopkins Univ. Press, Baltimore, 1999)

    Google Scholar 

  13. Silva, M. & Downing, J. A. CRC Handbook of Mammalian Body Mass (CRC Press, Boca Raton, 1995)

    Google Scholar 

  14. Jenkins, F. A. Jr Limb posture and locomotion in the Virginia opossum (Didelphis marsupialis) and in other non-cursorial mammals. J. Zool. 165, 303–315 (1971)

    Article  Google Scholar 

  15. Fischer, M. S., Schilling, N., Schmidt, M., Dieter Haarhaus, D. & Witte, H. Basic limb kinematics of small therian mammals. J. Exp. Biol. 205, 1315–1338 (2002)

    PubMed  Google Scholar 

  16. Wilson, R. W. Late Cretaceous (Fox Hills) multituberculates from the Red Owl Local Fauna of western South Dakota. Dakoterra 3, 118–132 (1987)

    Google Scholar 

  17. Clemens, W. A., Wilson, G. P. & Molnar, R. E. An enigmatic (synapsid?) tooth from the Early Cretaceous of New South Wales, Australia. J. Vert. Paleontol. 23, 232–237 (2003)

    Article  Google Scholar 

  18. Jenkins, F. A. Jr & Schaff, C. R. The Early Cretaceous mammal Gobiconodon (Mammalia, Triconodonta) from the Cloverly Formation in Montana. J. Vert. Paleontol. 8, 1–24 (1988)

    Article  Google Scholar 

  19. Rougier, G. W. Vincelestes neuquenianus Bonaparte (Mammalia, Theria), un Primitivo Mammifero del Cretaccico Inferior de la Cuenca Neuqina PhD Thesis, Univ. Nacional de Buenos Aires, Buenos Aires (1993)

  20. Alexander, R. McN., Jayes, A. S., Maloiy, G. M. O. & Wathuta, E. M. Allometry of limb bones of mammals from shrews (Sorex) to elephant (Loxodonta). J. Zool. 189, 305–314 (1979)

    Article  Google Scholar 

  21. Van Valkenburgh, B. in Body Size in Mammalian Paleobiology: Estimation and Biological Implication (eds Damuth, J. & MacFadden, B. J.) 181–205 (Cambridge Univ. Press, Cambridge, 1990)

    Google Scholar 

  22. Coombs, W. P. Jr Juvenile specimens of the ornithischian dinosaur Psittacosaurus . Palaeontology 25, 89–107 (1982)

    Google Scholar 

  23. Carbone, C., Mace, G. M., Roberts, S. C. & Macdonald, D. W. Energetic constraints on the diet of terrestrial carnivores. Nature 402, 286–288 (1999)

    Article  ADS  CAS  Google Scholar 

  24. Van Valkenburgh, B. & Jenkins, I. Evolutionary patterns in the history of Permo-Triassic and Cenozoic synapsid predators. Paleontol. Soc. Pap. 8, 267–288 (2002)

    Google Scholar 

  25. Reilly, S. M., McBrayer, L. D. & White, T. D. Prey processing in amniotes: biomechanical and behavioral patterns of food reduction. Comp. Biochem. Physiol. A Mol. Integr. Physiol. 128, 397–415 (2001)

    Article  CAS  Google Scholar 

  26. Van Valkenburgh, B., Sacco, T. & Wang, X.-M. Pack hunting in Miocene Borophagine dogs: Evidence from craniodental morphology and body size. Bull. Am. Mus. Nat. Hist. 279, 147–162 (2004)

    Article  Google Scholar 

  27. Damuth, J. & MacFadden, B. J. in Body Size in Mammalian Paleobiology: Estimation and Biological Implication (eds Damuth, J. & MacFadden, B. J.) 1–10 (Cambridge Univ. Press, Cambridge, 1990)

    Google Scholar 

  28. Lillegraven, J. A., Kielan-Jaworowska, Z. & Clemens, W. A. (eds) Mesozoic Mammals: The First Two-thirds of Mammalian History (Univ. California Press, Berkeley, 1979)

  29. Crompton, A. W. in Comparative Physiology: Primitive Mammals (eds Schmidt-Nielsen, K., Bolis, L. & Taylor, C. R.) 1–12 (Cambridge Univ. Press, Cambridge, 1980)

    Google Scholar 

  30. Eisenberg, J. F. in Body Size in Mammalian Paleobiology: Estimation and Biological Implication (eds Damuth, J. & MacFadden, B. J.) 25–38 (Cambridge Univ. Press, Cambridge, 1990)

    Google Scholar 

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Acknowledgements

We thank M.-M. Chang, Z.-H. Zhou, X.-L. Wang, X. Xu, F.-C. Zhang, Y. Wang, F. Jin and J.-Y. Zhang for help coordinating the research and fieldwork; X. Xu, X.-L. Wang, F.-C. Zhang, Z.-H. Zhou, and M. Norell for discussions on the research subject, and S.-H. Xie, S.-J. Li and A. Davidson for specimen preparation. This work was supported by funding from the Chinese Ministry of Science and Technology, the National Natural Science Foundation of China and the Chinese Academy of Sciences. Y.H. is also supported by a fellowship from the American Museum of Natural History, through the City University of New York.

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Correspondence to Yaoming Hu.

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Supplementary Information Notes

This Supplementary Information text includes: (I) body mass estimation for two species of Repenomamus; (II) stomach content preparation and identification for R. robustus (IVPP V 13605); (III) Data sources for Figure 4 (sizes of the lower jaws of representative Mesozoic mammals and relatives). The file contains six figures. (DOC 1625 kb)

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Hu, Y., Meng, J., Wang, Y. et al. Large Mesozoic mammals fed on young dinosaurs. Nature 433, 149–152 (2005). https://doi.org/10.1038/nature03102

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