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The Pleistocene serpent Wonambi and the early evolution of snakes


The Madtsoiidae were medium sized to gigantic snakes with a fossil record extending from the mid-Cretaceous to the Pleistocene, and spanning Europe, Africa, Madagascar, South America and Australia1,2,3. This widely distributed group survived for about 90 million years (70% of known ophidian history), and potentially provides important insights into the origin and early evolution of snakes. However, madtsoiids are known mostly from their vertebrae, and their skull morphology and phylogenetic affinities have been enigmatic. Here we report new Australian material of Wonambi, one of the last-surviving madtsoiids4,5,6, that allows the first detailed assessment of madtsoiid cranial anatomy and relationships. Despite its recent age, which could have overlapped with human history in Australia, Wonambi is one of the most primitive snakes known—as basal as the Cretaceous forms Pachyrhachis7 and Dinilysia8. None of these three primitive snake lineages shows features associated with burrowing, nor do any of the nearest lizard relatives of snakes (varanoids). These phylogenetic conclusions contradict the widely held ‘subterranean’ theory of snake origins9,10,11,12, and instead imply that burrowing snakes (scolecophidians and anilioids) acquired their fossorial adaptations after the evolution of the snake body form and jaw apparatus in a large aquatic or (surface-active) terrestrial ancestor.

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Figure 1: Reconstruction of the skull of Wonambi naracoortensis Smith, 1976.
Figure 2: Selected elements of Wonambi exhibiting phylogenetically important characters.
Figure 3: Cladogram (strict consensus of two most parsimonious trees, each with length = 649, consistency index = 0.49, retention index = 0.66 ) showing relationships among snake lineages and the very basal position of madtsoiids.


  1. Rage, J. C. Handbuch der Paläoherpetologie. Teil 11. Serpentes (Gustav Fischer, Stuttgart, 1984).

    Google Scholar 

  2. McDowell, S. B. in Snakes: Ecology and Evolutionary Biology (eds Seigel, R. A., Collins, J. T. C. & Novak, S. S.) 1–50 (Macmillan, New York, 1987).

    Google Scholar 

  3. Rage, J. C. Fossil snakes from the Paleocene of São José de Itaboraí, Brazil. Part I. Madtsoiidae, Aniliidae. Palaeovertebrata 27, 109–144 (1998).

    Google Scholar 

  4. Smith, M. J. Small fossil vertebrates from Victoria Cave, Naracoorte, South Australia. IV. Reptiles. Trans. R. Soc. S. Aust. 100, 39–51 (1976).

    ADS  Google Scholar 

  5. Barrie, D. J. Skull elements and associated remains of the Pleistocene boid snake Wonambi naracoortensis. Mem. Qd Mus. 28, 139 –151 (1990).

    Google Scholar 

  6. Scanlon, J. D. First records from Wellington Caves, New South Wales, of the extinct madtsoiid snake Wonambi naracoortensis Smith, 1976. Proc. Linn. Soc. NSW 115, 233–238 ( 1995).

    Google Scholar 

  7. Lee, M. S. Y. & Caldwell, M. W. Anatomy and relationships of Pachyrhachis problematicus, a primitive snake with hindlimbs. Phil. Trans. R. Soc. Lond. B 353, 1521– 1552 (1998).

    Article  Google Scholar 

  8. Estes, R., Frazzetta, T. H. & Williams, E. E. Studies on the fossil snake Dinilysia patagonica Woodward: Part 1. Cranial morphology. Bull. Mus. Comp. Zool. Harv. 140, 25–74 ( 1970).

    Google Scholar 

  9. Walls, G. L. Ophthalmological implications for the early history of snakes. Copeia 1940, 1–8 ( 1940).

    Article  Google Scholar 

  10. Bellairs, A. d'A. & Underwood, G. The origin of snakes. Biol. Rev. 26, 193– 237 (1951).

    Article  CAS  Google Scholar 

  11. Underwood, G. A Contribution to the Classification of Snakes (British Museum (Natural History), London, 1967).

    Google Scholar 

  12. Rieppel, O. A review of the origin of snakes. Evol. Biol. 22, 37–130 (1988).

    Article  Google Scholar 

  13. Archer, M., Hand, S. J., Godthelp, H. & Creaser, P. in Actes du Congrès Biochrom '97 (eds. Aguilar, J.-P., Legendre, S. & Michaux, J.) 131–152 (École Pratique des Hautes Études Institute de Montpelier, Montpelier, 1997).

    Google Scholar 

  14. Scanlon, J. D. Nanowana gen. nov., small madtsoiid snakes from the Miocene of Riversleigh: sympatric species with divergently specialised dentition. Mem. Qd Mus. 41, 393–412 ( 1997).

    Google Scholar 

  15. LaDuke, T. C. The fossil snakes of Pit 91, Rancho La Brea, California. Nat. Hist. Mus. LA County Contrib. Sci. 424, 1– 28 (1991).

    Google Scholar 

  16. Frazzetta, T. H. Studies on the fossil snake Dinilysia patagonica Woodward. II. Jaw machinery in the earliest snakes. Forma et Functio 3, 205–221 (1970).

    Google Scholar 

  17. Cundall, D. Feeding behaviour in Cylindrophis and its bearing on the evolution of alethinophidian snakes. J. Zool. 237, 353–376 (1995).

    Article  Google Scholar 

  18. Lee, M. S. Y. Convergent evolution and character correlation in burrowing reptiles: towards a resolution of squamate phylogeny. Biol. J. Linn. Soc. 65, 369–453 (1998).

    Article  Google Scholar 

  19. Underwood, G. in Morphology and Biology of Reptiles (eds Bellairs, A. d'A. & Cox, C. B.) 151–175 (Academic, London, 1976).

    Google Scholar 

  20. Woodward, A. S. On some extinct reptiles from Patagonia, of the genera Miolania, Dinilysia, and Genyodectes. Proc. Zool. Soc. Lond. 1901, 169–184 (1901).

    Article  Google Scholar 

  21. Zaher, H. The phylogenetic position of Pachyrhachis within snakes (Squamata, Lepidosauria). J. Vert. Paleontol. 18, 1 –3 (1998).

    Article  Google Scholar 

  22. Kluge, A. G. Boine snake phylogeny and research cycles. Misc. Publ. Mus. Zool. Univ. Michigan 178, 1–58 (1991).

    Google Scholar 

  23. Cundall, D., Wallach, V. & Rossman, D. S. The systematic relationships of the snake genus Anomochilus. Zool. J. Linn. Soc. 109, 275–299 (1993).

    Article  Google Scholar 

  24. Heise, P. J., Maxson, L. R., Dowling, H. G. & Hedges, S. B. Higher-level snake phylogeny inferred from mitochondrial DNA sequences of 12S rRNA and 16S rRNA genes. Mol. Biol. Evol. 12, 259–265 (1995).

    CAS  PubMed  Google Scholar 

  25. Hecht, M. K. The vertebral morphology of the Cretaceous snake, Dinilysia patagonica Woodward. N. Jb. Geol. Paläont. Mh. 1982, 523–532 (1982).

    Google Scholar 

  26. Nopcsa, F. Eidolosaurus und Pachyophis. Zwei neue Neocom-Reptilien. Palaeontographica 65, 99–154 (1923).

    Google Scholar 

  27. Cope, E. D. On the reptilian orders Pythonomorpha and Streptosauria. Proc. Boston Soc. Nat. Hist. 12, 250–266 (1869).

    Google Scholar 

  28. Janensch, W. Über Archaeophis proavus Mass., eine Schlange aus dem Eocän des Monte Bolca. Beitr. z. Paläont. Geol. Österreich-Ungarns 19, 1–33 (1906 ).

    Google Scholar 

  29. Wallach, V. & Rainer, G. Visceral anatomy of the Malaysian snake genus Xenophidion, including a cladistic analysis and allocation to a new family. Amphibia–Reptilia 19, 385–404 (1998).

    Article  Google Scholar 

  30. Swofford, D. L. PAUP* Version 4—Phylogenetic Analysis Using Parsimony (*and Other Methods). Computer program and documentation. (Sinauer, Sunderland, Massachusetts, 1999).

    Google Scholar 

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We thank D. J. Barrie, M. Archer, R. E. Molnar, N. Pledge and R. T. Wells for access to materials, and V. Wallach, G. Underwood, J.-C. Rage, D. J. Barrie, S. E. Evans, H. W. Greene, D. Cundall, M. W. Caldwell and A. G. Kluge for discussion. This research was supported by Australian Research Council grants to M.L. and J.S. Work at Riversleigh was supported by the Australian Research Council and University of New South Wales (to M. Archer), and work at Naracoorte by Flinders University, the South Australian Museum, L. and G. Henschke, the Barrie family and numerous volunteers.

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Scanlon, J., Lee, M. The Pleistocene serpent Wonambi and the early evolution of snakes . Nature 403, 416–420 (2000).

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