Deep-time evolution of regeneration and preaxial polarity in tetrapod limb development


Among extant tetrapods, salamanders are unique in showing a reversed preaxial polarity in patterning of the skeletal elements of the limbs, and in displaying the highest capacity for regeneration, including full limb and tail regeneration. These features are particularly striking as tetrapod limb development has otherwise been shown to be a highly conserved process1,2. It remains elusive whether the capacity to regenerate limbs in salamanders is mechanistically and evolutionarily linked to the aberrant pattern of limb development; both are features classically regarded as unique to urodeles3. New molecular data suggest that salamander-specific orphan genes play a central role in limb regeneration and may also be involved in the preaxial patterning during limb development4,5. Here we show that preaxial polarity in limb development was present in various groups of temnospondyl amphibians of the Carboniferous and Permian periods, including the dissorophoids Apateon and Micromelerpeton, as well as the stereospondylomorph Sclerocephalus. Limb regeneration has also been reported in Micromelerpeton6, demonstrating that both features were already present together in antecedents of modern salamanders 290 million years ago. Furthermore, data from lepospondyl ‘microsaurs’ on the amniote stem indicate that these taxa may have shown some capacity for limb regeneration and were capable of tail regeneration7, including re-patterning of the caudal vertebral column that is otherwise only seen in salamander tail regeneration. The data from fossils suggest that salamander-like regeneration is an ancient feature of tetrapods that was subsequently lost at least once in the lineage leading to amniotes. Salamanders are the only modern tetrapods that retained regenerative capacities as well as preaxial polarity in limb development.

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Figure 1: Phylogenetic tree depicting major groups of tetrapods.
Figure 2: Ossification patterns in the limbs of Micromelerpeton and Sclerocephalus.
Figure 3: Tail regeneration in the microsaur taxa Microbrachis and Hyloplesion in comparison with an extant salamander.


  1. 1

    Shubin, N., Tabin, C. & Carroll, S. B. Fossils, genes and the evolution of animal limbs. Nature 388, 639–648 (1997)

    ADS  CAS  Article  Google Scholar 

  2. 2

    Zeller, R., Lopez-Rios, J. & Zuniga, A. Vertebrate limb bud development: moving towards integrative analysis of organogenesis. Nature Rev. Genet. 10, 845–858 (2009)

    CAS  Article  Google Scholar 

  3. 3

    Fröbisch, N. B. & Shubin, N. H. Salamander limb development: integrating genes, morphology, and fossils. Dev. Dyn. 240, 1087–1099 (2011)

    Article  Google Scholar 

  4. 4

    Brockes, J. P. & Gates, P. Mechanisms underlying vertebrate limb regeneration: lessons from the salamander. Biochem. Soc. Trans. 42, 625–630 (2014)

    CAS  Article  Google Scholar 

  5. 5

    Brockes, J. in Salamanders in Regeneration Research: Methods and Protocols (eds Kumar, A. & András, S. ) Ch. 1 (Springer, 2015)

    Google Scholar 

  6. 6

    Fröbisch, N. B., Bickelmann, C. & Witzmann, F. Early evolution of limb regeneration in tetrapods: evidence from a 300-million-year-old amphibian. Proc. Biol. Sci. (2014)

  7. 7

    Carroll, R. L. & Gaskill, P. The Order Microsauria. 122 (American Philosophical Society, 1978)

    Google Scholar 

  8. 8

    Shubin, N. H. & Alberch, P. A morphogenetic approach to the origin and basic organisation of the tetrapod limb. Evol. Biol. 20, 319–387 (1986)

    Google Scholar 

  9. 9

    Shubin, N. H. & Wake, D. B. in Amphibian Biology Vol. 5 (eds Heatwole, H. & Davies, M. ) 1782–1808 (Surrey Beatty & Sons PTY limited, 2003)

    Google Scholar 

  10. 10

    Gardiner, D. M. & Bryant, S. V. in Fins into Limbs (ed. Hall, B. K. ) 163–182 (Univ. Chicago Press, 2007)

    Google Scholar 

  11. 11

    Simon, A. & Tanaka, E. M. Limb regeneration. Wiley Interdiscip. Rev. Dev. Biol. 2, 291–300 (2013)

    Article  Google Scholar 

  12. 12

    Anderson, J. S., Reisz, R. R., Fröbisch, N. B., Scott, D. & Sumida, S. S. A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders. Nature 453, 515–518 (2008)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Ruta, M. & Coates, M. I. Dates, nodes and character conflict: addressing the lissamphibian origin problem. J. Syst. Palaeontology 5, 69–122 (2007)

    Article  Google Scholar 

  14. 14

    Marjanović, D. & Laurin, M. The origin(s) of extant amphibians: a review with emphasis on the “lepospondyl hypothesis”. Geodiversitas 35, 207–272 (2013)

    Article  Google Scholar 

  15. 15

    Schoch, R. R. Life cycles, plasticity and palaeoecology in temnospondyl amphibians. Palaeontology 57, 517–529 (2014)

    Article  Google Scholar 

  16. 16

    Fröbisch, N. B., Carroll, R. L. & Schoch, R. R. Limb ossification in the Paleozoic branchiosaurid Apateon (Temnospondyli) and the early evolution of preaxial dominance in tetrapod limb development. Evol. Dev. 9, 69–75 (2007)

    Article  Google Scholar 

  17. 17

    Fröbisch, N. B. Ossification patterns in the tetrapod limb – conservation and divergence from morphogenetic events. Biol. Rev. Camb. Philos. Soc. 83, 571–600 (2008)

    Article  Google Scholar 

  18. 18

    Schmalhausen, J. J. Die Entwicklung des Extremitätenskelettes von Salamandrella kayserlingii. Anat. Anz. 37, 431–446 (1910)

    Google Scholar 

  19. 19

    Schoch, R. R. Early larval ontogeny of the Permo-Carboniferous temnospondyl Sclerocephalus. Paleontology 46, 1055–1072 (2003)

    Article  Google Scholar 

  20. 20

    Witzmann, F. & Pfretzschner, H.-U. Larval ontogeny of Micromelerpeton credneri (Temnospondyli, Dissorophoidea). J. Vert. Paleontol. 23, 750–768 (2003)

    Article  Google Scholar 

  21. 21

    Olori, J. Skeletal morphogenesis of Microbrachis and Hyloplesion (Tetrapoda: Lepospondyli), and implications for the developmental patterns of extinct, early tetrapods. PLoS ONE 10, e0128333 (2015)

    Article  Google Scholar 

  22. 22

    Conant, E. B. Regeneration in the African lungfish, Protopterus. I. Gross aspects. J. Exp. Zool. 174, 15–31 (1970)

    Article  Google Scholar 

  23. 23

    Holtzer, H., Holtzer, S. & Avery, G. An experimental analysis of the development of the spinal column IV. Morphogenesis of tail vertebrae during regeneration. J. Morphol. 96, 145–171 (1955)

    Article  Google Scholar 

  24. 24

    Vaglia, J. L., Babcock, S. K. & Harris, R. N. Tail development and regeneration throughout the life cycle of the four-toed salamander Hemidactylium scutatum. J. Morphol. 233, 15–29 (1997)

    Article  Google Scholar 

  25. 25

    Beck, C. W., Izpisúa Belmonte, J. C. & Christen, B. Beyond early development: Xenopus as an emerging model for the study of regenerative mechanisms. Dev. Dyn. 238, 1226–1248 (2009)

    CAS  Article  Google Scholar 

  26. 26

    Fisher, R. E. et al. A histological comparison of the original and regenerated tail in the green anole, Anolis carolinensis. Anat. Rec. 295, 1609–1619 (2012)

    Article  Google Scholar 

  27. 27

    Alibardi, L. Morphological and Cellular Aspects of Tail and Limb Regeneration in Lizards. (Springer, 2010)

    Google Scholar 

  28. 28

    Holtzer, S. W. The inductive activity of the spinal cord in urodele tail regeneration. J. Morphol. 99, 1–39 (1956)

    Article  Google Scholar 

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We thank B. Ekrt, J. Müller, U. Göhlich, S. Walsh, C. Mehling, P. Barrett and R. Schoch for access to the collections under their care. H. J. Götz took the photograph in Fig. 3c; S. Lokatis took the photograph in Fig. 3b. This research was funded by an DFG Emmy Noether Grant (FR 2647/5-1) to N.B.F.; the Jackson School of Geosciences, the Banks Fellowship, Society of Vertebrate Paleontology Estes Memorial Grant and Paleontological Society Lane Student Award to J.C.O.; and the Feodor-Lynen Fellowship of the Alexander von Humboldt Foundation to F.W.

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N.B.F., C.B. and F.W. designed the research; N.B.F., C.B., J.C.O. and F.W. performed the research; N.B.F. wrote the manuscript; C.B., J.C.O. and F.W. contributed to the manuscript.

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Correspondence to Nadia B. Fröbisch.

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The authors declare no competing financial interests.

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Fröbisch, N., Bickelmann, C., Olori, J. et al. Deep-time evolution of regeneration and preaxial polarity in tetrapod limb development. Nature 527, 231–234 (2015).

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