Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Cretaceous age for the feathered dinosaurs of Liaoning, China


The ancient lake beds of the lower part of the Yixian Formation, Liaoning Province, northeastern China, have yielded a wide rangeof well-preserved fossils: the ‘feathered’ dinosaurs Sinosauropteryx1, Protarchaeopteryx and Caudipteryx2, the primitive birds Confuciusornis3 and Liaoningornis4, the mammal Zhangheotherium5 and the reportedly oldest flowering plant, Archaefructus6. Equally well preserved in the lake beds are a wide range of fossil plants, insects, bivalves, conchostracans, ostracods, gastropods, fish, salamanders, turtles, lizards, the frog Callobatrachus7 and the pterosaur Eosipterus1,8. This uniquely preserved assemblage of fossils is providing newinsight into long-lived controversies over bird–dinosaur relationships1,2, the early diversification of birds3,9,10 and the origin and evolution of flowering plants6. Despite the importance of this fossil assemblage, estimates of its geological age have varied widely from the Late Jurassic to the Early Cretaceous. Here we present the first 40Ar/39Ar dates unambiguously associated with the main fossil horizons of the lower part of the Yixian Formation, and thus, for the first time, provide accurate age calibration of this important fauna. The results of this dating study indicate that the lower Yixian fossil horizons are not Jurassic but rather are at least 20 Myr younger, placing them within middle Early Cretaceous time.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Map of the Sihetun area, Liaoning Province, northeastern China.
Figure 2: Stratigraphic correlation of the main fossil-bearing layers of the lower Yixian Formation.
Figure 3: 40Ar/39Ar dating results.

Similar content being viewed by others


  1. Chen, P.-J., Dong, Z.-M. & Zhen, S.-N. An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China. Nature 391, 147–152 (1998).

    Article  ADS  CAS  Google Scholar 

  2. Ji, Q., Currie, P. J., Norell, M. A. & Ji, S.-A. Two feathered dinosaurs from northeastern China. Nature 393, 753–761 (1998).

    Article  ADS  Google Scholar 

  3. Hou, L.-H., Zhou, Z.-H., Martin, L. D. & Feduccia, A. Abeaked bird from the Jurassic of China. Nature 377, 616–618 (1995).

    Article  ADS  Google Scholar 

  4. Hou, L.-H. Acarnate bird from the Upper Jurassic of western Liaoning, China. Chinese Sci. Bull. 41, 1861–1864 (1996).

    Google Scholar 

  5. Hu, Y.-M., Wang, Y.-Q., Luo, Z.-X. & Li, C.-K. Anew symmetrodont mammal from China and its implications for mammal evolution. Nature 390, 137–142 (1997).

    Article  ADS  CAS  Google Scholar 

  6. Sun, G., Dilcher, D. L., Zheng, S.-L. & Zhou, Z.-K. In search of the first flower: A Jurassic angiosperm, Archaefructus, from northeast China. Science 282, 1692–1695 (1998).

    Article  ADS  CAS  Google Scholar 

  7. Wang, Y. & Gao, K.-Q. Earliest Asian discoglossid frog from western Liaoning. Chinese Sci. Bull. 44, 636–642 (1999).

    Article  ADS  Google Scholar 

  8. Ji, S.-A. & Ji, Q. Discovery of a new pterosaur from western Liaoning, China. Acta Geol. Sin. 71, 1–5 (1997).

    Google Scholar 

  9. Hou, L.-H., Martin, L. D., Zhou, Z.-H. & Feduccia, A. Early adaptive radiation of birds: evidence from fossils from northeastern China. Science 274, 1164–1167 (1996).

    Article  ADS  CAS  Google Scholar 

  10. Sereno, P. C. & Rao, C.-G. Early evolution of avian flight and perching: new evidence from the Lower Cretaceous of China. Science 255, 845–848 (1992).

    Article  ADS  CAS  Google Scholar 

  11. Wang, X.-L. et al . Stratigraphic sequence and vertebrate-bearing beds of the lower part of the Yixian Formation, in Sihetun and neighboring area, western Liaoning, China. Vert. PalAsiat. 36, 81–96 (1998).

    Google Scholar 

  12. Chen, P.-J. Distribution and migration of the Jehol Fauna with reference to nonmarine Jurassic-Cretaceous boundary in China. Acta Palaeont. Sin. 27, 659–683 (1988).

    Google Scholar 

  13. Wang, S.-E. Origin, evolution and mechanism of the Jehol Fauna. Acta Geol. Sin. 63, 351–360 (1990).

    Google Scholar 

  14. Yu, J.-S., Dong, G.-Y. & Yao, P.-Y. in Mesozoic Stratigraphy and Palaeontology of Western Liaoning Vol. 3, 1–28 (Geological Publishing House, Beijing, (1987).

    Google Scholar 

  15. Zhang, L.-J. in Mesozoic Stratigraphy and Palaeontology of Western Liaoning Vol. 2, 1–212 (Geological Publishing House, Beijing, (1985).

    Google Scholar 

  16. Ren, D. Flower-associated Brachycera flies as fossil evidence for Jurassic angiosperm origins. Science 280, 85–88 (1998).

    Article  ADS  CAS  Google Scholar 

  17. Wang, W.-L. in Mesozoic Stratigraphy and Palaeontology of Western Liaoning Vol. 3, 134–201 (Geological Publishing House, Beijing, (1987).

    Google Scholar 

  18. Hao, Y.-C., Su, D.-Y., Li, Y.-G. & Li, P.-X. Stratigraphical division of non-marine Cretaceous and the Juro-Cretaceous boundary in China. Acta Geol. Sin. 56, 187–199 (1982).

    Google Scholar 

  19. Li, P.-X., Su, D.-Y., Li, Y.-G. & Yu, J.-X. The chronostratigraphic status of the Lycoptera-bearing bed. Acta Geol. Sin. 68, 87–100 (1994).

    Google Scholar 

  20. Mao, S., Yu, J. & Lentin, J. K. Palynological interpretation of Early Cretaceous non-marine strata of northeast China. Rev. Paleobot. Palynol. 65, 115–118 (1990).

    Article  Google Scholar 

  21. Wellnhoffer, P. Das siebte Examplar von Archaeopteryx aux den Solnhofener Schichten. Archaeopteryx 11, 1–48 (1993).

    Google Scholar 

  22. Xu, X. & Wang, X.-L. New psittacosaur (Ornithischia, Ceratopsia) occurrence from the Yixian Formation of Liaoning, China, and its stratigraphical significance. Vert. PalAsiat. 36, 147–158 (1997).

    Google Scholar 

  23. Wang, D.-F. On the age of the Rehe Group in western Liaoning Province, China. Bull. Chinese Acad. Geol. Sci. 7, 65–82 (1983).

    Google Scholar 

  24. Wang, D.-F. & Diao, N.-C. in Scientific Papers on Geology for International Exchange Vol. 5, 1–12 (Geological Publishing House, Beijing, (1984).

    Google Scholar 

  25. Gradstein, F. M. et al . in Geochronology, Time Scales and Global Stratigraphic Correlation (eds Berggren, W. A, Kent, D. V., Aubry, M.-P. & Hardenbol, J.) 95–126 (S.E.P.M. Spec. Publ. No. 54, (1995).

    Book  Google Scholar 

  26. Smith, P. et al . Dates and rates in ancient lakes: 40Ar/39Ar evidence for an Early Cretaceous age for the Jehol Group, northeast China. Can. J. Earth Sci. 32, 1426–1431 (1995).

    Article  ADS  Google Scholar 

  27. Renne, P. R. et al . Intercalibration of standards, absolute ages and uncertainties in 40Ar/39Ar dating. Chem. Geol. 145, 117–152 (1998).

    Article  ADS  CAS  Google Scholar 

  28. McDougall, I. & Harrison, T. M. Geochronology and Thermochronology (Oxford Univ. Press, New York, (1988).

    Google Scholar 

  29. Roddick, J. C. High precision intercalibration of 40Ar/39Ar standards. Geochim. Cosmochim. Acta 47, 887–898 (1983).

    Article  ADS  CAS  Google Scholar 

  30. Sun, G. & Dilcher, D. L. Early angiosperms from the Lower Cretaceous of Jixi, China and their significance for the study of the earliest occurrence of angiosperms in the world. Palaeobotany 45, 393–399.

Download references


We thank all the members of the IVPP field crew, and M. M. Chang, Z. Luo and S. Kelley for discussion and comment on this study. This research was funded, in part, by the Chinese Academy of Sciences and the National Science Foundation, Earth Science Program.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Carl C. Swisher III.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Swisher, C., Wang, Yq., Wang, Xl. et al. Cretaceous age for the feathered dinosaurs of Liaoning, China. Nature 400, 58–61 (1999).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing