Polydactyly in the earliest known tetrapod limbs


NEW specimens of the earliest known tetrapod limbs shows them to be polydactylous. The forelimb of Acanthostega has eight digits and the hindlimb of Ichthyostega has seven. Both of these come from the Upper Devonian of East Greenland, complementing the only other known Devonian tetrapod limb, that of Tulerpeton from Russia1, which has six digits. The morphology of the specimens suggests that limbs with digits may have been adaptations to an aquatic rather than a terrestrial environment. The pattern of digits corresponds to a recently proposed model for limb development2 in which digit number is unspecified, rather than earlier models3–10 which are rejected because they postulate a fixed number of elements in the ancestral limb. We challenge pentadactyly as primitive for tetrapods3,11. The form of these limbs suggests early specialization in the evolution of the tetrapod limb bud.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Lebedev, O. A. Dokl. Akad. Nauk SSSR 278, 1407–1473 (1984).

    Google Scholar 

  2. 2

    Shubin, N. H. & Alberch, P. Evol. Biol. 20, 319–387 (1986).

    Google Scholar 

  3. 3

    Jarvik, E. Basic Structure and Evolution of Vertebrates Vol. 2 (Academic, London, 1980).

    Google Scholar 

  4. 4

    Gegenbaur, C. Morph. Jb. 2, 396–420 (1876).

    Google Scholar 

  5. 5

    Watson, D. M. S. Anat. Anz. 44, 24–27 (1913).

    Google Scholar 

  6. 6

    Gregory, W. K., Miner, R. W. & Noble, G. K. Bull. Am. Mus. nat. Hist. 48, 279–288 (1923).

    Google Scholar 

  7. 7

    Gregory, W. K. & Raven, H. C. Ann. N. Y. Acad. Sci. 42, 273–360 (1941).

    ADS  Article  Google Scholar 

  8. 8

    Holmgren, N. Acta zool. 14, 185–295 (1933).

    Article  Google Scholar 

  9. 9

    Westoll, T. S. Proc. R. Soc. B131, 373–393 (1943).

    ADS  Google Scholar 

  10. 10

    Steiner, H. Rev. Suisse. Zool. 41, 383–396 (1934).

    Article  Google Scholar 

  11. 11

    Goodrich, E. S. Studies on the Structure and Development of Vertebrates (Macmillan, London, 1930).

    Google Scholar 

  12. 12

    Panchen, A. L. Nature 333, 704 (1988).

    ADS  Article  Google Scholar 

  13. 13

    Jarvik, E. Basic Structure and Evolution of Vertebrates Vol. 1 (Academic, London, 1980).

    Google Scholar 

  14. 14

    Smithson, T. R. Zool. J. Linn. Soc. 85, 317–410 (1985).

    Article  Google Scholar 

  15. 15

    Holmes, R. Phil. Trans. R. Soc. B306, 413–527 (1984).

    Article  Google Scholar 

  16. 16

    Andrews, S. M. & Westoll, T. S. Trans. R. Soc. Edinb. 68, 207–329 (1970).

    Article  Google Scholar 

  17. 17

    Panchen, A. L. & Smithson, T. R. Biol. Rev. 62, 341–438 (1987).

    Article  Google Scholar 

  18. 18

    Rackoff, J. S. in The Terrestrial Environment and the Origin of Land Vertebrates (ed. Panchen, A. L.) 255–292 (Academic, London, 1980).

    Google Scholar 

  19. 19

    Wood, S. P., Panchen, A. L. & Smithson, T. R. Nature 314, 355–356 (1985).

    ADS  Article  Google Scholar 

  20. 20

    Smithson, T. R. Nature 342, 676–678 (1989).

    ADS  Article  Google Scholar 

  21. 21

    Godfrey, S. J. Phil. Trans. R. Soc. B323, 75–133 (1989).

    Article  Google Scholar 

  22. 22

    Panchen, A. L. & Smithson, T. R. in The Phytogeny and Classification of the Tetrapods. Volume 1: Amphibians, Reptiles, Birds (ed. Benton, M. J.) 1–32 (Clarendon, Oxford, 1988).

    Google Scholar 

  23. 23

    Bjerring, H. C. in Evolutionary Biology of Primitive Fishes (eds Foreman, R. E. et al.) (Plenum, New York, 1985).

    Google Scholar 

  24. 24

    Edwards, J. L. Am. Zool. 29, 235–254 (1989).

    Article  Google Scholar 

  25. 25

    Muller, G. B. & Alberch, P. J. Morph. 203, 151–164 (1990).

    Article  Google Scholar 

  26. 26

    Hinchliffe, J. R. & Griffiths, P. J. in Development and Evolution (eds Goodwin, B. C. et al.) 99–121 (Cambridge University Press, Cambridge, 1983).

    Google Scholar 

  27. 27

    Hinchliffe, J. R. in Fortschritte der Zoologie Vol. 35 (eds Splechtna, H. & Hilgers, C. H.) 226–229 (Gustav Fischer Verlag, Stuttgart, 1989).

    Google Scholar 

  28. 28

    Oster, G. F. et al. Evolution 42, 862–884 (1988).

    Article  Google Scholar 

  29. 29

    Goodwin, B. C. & Trainor, L. E. H. in Development and Evolution (eds Goodwin, B. C. et al.) 75–98 (Cambridge University Press, Cambridge, 1983).

    Google Scholar 

  30. 30

    Hinchliffe, J. R. in Complex Organismal Functions: Integration and Evolution in Vertebrates (eds Wake, D. B. & Roth, G.) 171–189 (Wiley, Chichester, 1989).

    Google Scholar 

  31. 31

    Danforth, C. H. Am. J. Anat. 80, 143–171 (1947).

    CAS  Article  Google Scholar 

  32. 32

    Rosen, D. E. et al. Bull. Am. Mus. nat. Hist. 67, 159–276 (1981).

    Google Scholar 

  33. 33

    Brickell, P. M. & Tickle, C. BioEssays 11, 145–149 (1989).

    CAS  Article  Google Scholar 

  34. 34

    Wolpert, L. in Development and Evolution (eds Goodwin, B. C. et al.) 47–51 (Cambridge University Press, Cambridge, 1983).

    Google Scholar 

  35. 35

    Saunders, J. W. in Vertebrate Limb and Somite Morphogenesis (eds Ede, D. A. et al.) 1–24 (Cambridge University Press, Cambridge, 1977).

    Google Scholar 

  36. 36

    Hinchliffe, J. R. & Johnson, D. R. The Development of the Vertebrate Limb (Clarendon, Oxford, 1980).

    Google Scholar 

  37. 37

    Holder, N. J. theor. Biol. 104, 451–471 (1983).

    CAS  Article  Google Scholar 

Download references

Author information



Rights and permissions

Reprints and Permissions

About this article

Cite this article

Coates, M., Clack, J. Polydactyly in the earliest known tetrapod limbs. Nature 347, 66–69 (1990). https://doi.org/10.1038/347066a0

Download citation

Further reading


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.


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