Abstract
Snakes are the most diverse group of lizards1, but their origins and early evolution remain poorly understood owing to a lack of transitional forms. Several major issues remain outstanding, such as whether snakes originated in a marine2,3,4 or terrestrial5,6 environment and how their unique feeding mechanism evolved1,7,8. The Cretaceous Coniophis precedens was among the first Mesozoic snakes discovered9, but until now only an isolated vertebra has been described9,10 and it has therefore been overlooked in discussions of snake evolution. Here we report on previously undescribed material11 from this ancient snake, including the maxilla, dentary and additional vertebrae. Coniophis is not an anilioid as previously thought11; a revised phylogenetic analysis of Ophidia shows that it instead represents the most primitive known snake. Accordingly, its morphology and ecology are critical to understanding snake evolution. Coniophis occurs in a continental floodplain environment, consistent with a terrestrial rather than a marine origin; furthermore, its small size and reduced neural spines indicate fossorial habits, suggesting that snakes evolved from burrowing lizards. The skull is intermediate between that of lizards and snakes. Hooked teeth and an intramandibular joint indicate that Coniophis fed on relatively large, soft-bodied prey. However, the maxilla is firmly united with the skull, indicating an akinetic rostrum. Coniophis therefore represents a transitional snake, combining a snake-like body and a lizard-like head. Subsequent to the evolution of a serpentine body and carnivory, snakes evolved a highly specialized, kinetic skull, which was followed by a major adaptive radiation in the Early Cretaceous period. This pattern suggests that the kinetic skull was a key innovation that permitted the diversification of snakes.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
A conserved tooth resorption mechanism in modern and fossil snakes
Nature Communications Open Access 10 February 2023
-
First evidence of convergent lifestyle signal in reptile skull roof microanatomy
BMC Biology Open Access 30 November 2020
-
The evolution of the axial skeleton intercentrum system in snakes revealed by new data from the Cretaceous snakes Dinilysia and Najash
Scientific Reports Open Access 04 February 2019
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout





References
Greene, H. W. Snakes: the Evolution of Mystery in Nature (Univ. California Press, 1997)
Caldwell, M. W. & Lee, M. S. Y. A snake with legs from the marine Cretaceous of the Middle East. Nature 386, 705–709 (1997)
Cope, E. D. On the reptilian orders Pythonomorpha and Streptosauria. Proc. Bost. Soc. Nat. Hist. 12, 250–267 (1869)
Lee, M. S. Y. Molecular evidence and marine snake origins. Biol. Lett. 1, 227–230 (2005)
Apesteguía, S. & Zaher, H. A Cretaceous terrestrial snake with robust hindlimbs and a sacrum. Nature 440, 1037–1040 (2006)
Vidal, N. & Hedges, S. B. Molecular evidence for a terrestrial origin of snakes. Proc. R. Soc. Lond. B 271, S226–S229 (2004)
Lee, M. S. Y., Bell, G. L. & Caldwell, M. W. The origin of snake feeding. Nature 400, 655–659 (1999)
Cundall, D. & Greene, H. W. in Feeding: Form, Function, and Evolution in Terrestrial Vertebrates (ed. Schwenk, K. ) 293–333 (Academic, 2000)
Marsh, O. C. Notice of new reptiles from the Laramie Formation. Am. J. Sci. 43, 449–453 (1892)
Gilmore, C. W. Fossil snakes of North America. Geol. Soc. Am. Bull. 9, 1–96 (1938)
Estes, R. Fossil Vertebrates from the Late Cretaceous Lance Formation, Eastern Wyoming. Univ. Calif. Publ. Geol. Sci. 49, 140–141 (1964)
Zaher, H., Apesteguía, S. & Scanferla, C. A. The anatomy of the Upper Cretaceous snake Najash rionegrina Apesteguía & Zaher, 2006, and the evolution of limblessness in snakes. Zool. J. Linn. Soc. 156, 801–826 (2009)
Cundall, D. & Irish, F. in Biology of the Reptilia Vol. 20 (eds Gans, C., Gaunt, A. S. & Adler, K. ) 349–692 (Society for the Study of Amphibians and Reptiles, 2008)
Hoffstetter, R. in Traité de Paléontologie (ed. Piveteau, J. ) 606–662 (Maison et Cie, 1955)
Rage, J.-C. & Augé, M. Squamate reptiles from the middle Eocene of Lissieu (France). Geobios 43, 253–268 (2010)
Scanlon, J. D. & Lee, M. S. Y. Varanoid-like dentition in primitive snakes (Madtsoiidae). J. Herpetol. 36, 100–106 (2002)
Cundall, D. Feeding behavior in Cylindrophis and its bearing on the evolution of alethinophidian snakes. J. Zool. 237, 353–376 (1995)
Wilson, J. A., Mohabey, D. M., Peters, S. E. & Head, J. J. Predation upon hatchling dinosaurs by a new snake from the Late Cretaceous of India. PLoS Biol. 8, e1000322 (2010)
Zaher, H. & Scanferla, C. A. The skull of the Upper Cretaceous snake Dinilysia patagonica Smith-Woodward 1901, and its phylogenetic position revisited. Zool. J. Linn. Soc. 164, 194–238 (2012)
Scanlon, J. D. & Lee, M. S. Y. The Pleistocene serpent Wonambi and the early evolution of snakes. Nature 403, 416–420 (2000)
Scanlon, J. D. Skull of the large non-macrostomatan snake Yurlunggur from the Australian Oligocene. Nature 439, 839–842 (2006)
Rage, J.-C. & Albino, A. M. Dinilysia patagonica (Reptilia, Serpentes): matériel vertébral additionel du Crétacé supérieur d’Argentine. Étude complémentaire des vertèbres, variations intraspécifiques etintracolumnaires. Neues Jahrb. Geol. Paläontol. Monatsh. 1989, 433–447 (1989)
Hoffstetter, R. & Gasc, J.-P. Vertebrae and ribs of modern reptiles.. in Biology of the Reptilia Vol. 1 (ed. Gans, C. ) 201–310 (Academic, 1969).
Prasad, G. V. R. Rage, J.-C. Amphibians and squamates from the Maastrichtian of Naskal, India. Cretac. Res. 16, 95–107 (1995)
Caldwell, M. W. & Albino, A. M. Palaeoenvironment and palaeoecology of three Cretaceous snakes: Pachyophis, Pachyrhachis, and Dinilysia . Acta Palaeontol. Pol. 46, 203–218 (2001)
Kearney, M. Systematics of the Amphisbaenia (Lepidosauria: Squamata) based on morphological evidence from recent and fossil forms. Herpetological Monogr. 17, 1–74 (2003)
Rage, J.-C. & Escuil, F. The Cenomanian: stage of hindlimbed snakes. Carnets Géol. 2003, 2003/01. (2003)
Rage, J.-C. & Werner, C. Mid-Cretaceous (Cenomanian) snakes from Wadi Abu Hashim, Sudan: the earliest snake assemblage. Palaeontol. Afr. 35, 85–110 (1999)
Gardner, J. D. & Cifelli, R. L. A primitive snake from the Cretaceous of Utah. Spec. Pap. Palaeontol. 60, 87–100 (1999)
Acknowledgements
We thank the curators and staff of the American Museum of Natural History, the University of California Museum of Paleontology and the Yale Peabody Museum of Natural History, and the staff of Digimorph at the University of Texas at Austin, for specimen access. We are especially grateful to J. Head for discussions about snake vertebrae, which prevented a major error in the assignment of material to Coniophis. This research was funded in part by US NSF grant DEB-0132227 to J.A.G. N.R.L. was funded by the Yale Institute for Biospheric Studies.
Author information
Authors and Affiliations
Contributions
N.R.L. designed the research, identified specimens, collected data, performed the phylogenetic analysis and wrote the paper. B.-A.S.B. designed the research, collected data and wrote the paper. J.A.G. collected data, contributed data and wrote the paper.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information 1
This file contains Supplementary Text and Data 1-2, Supplementary Figures 1-2 and additional references. (PDF 554 kb)
Supplementary Information 2
This file contains Supplementary Text and Data, Supplementary Materials, Supplementary Results, a Supplementary Discussion and additional references. (PDF 1206 kb)
Supplementary Information 3
This file contains the Supplementary Character illustrations 155-228. (PDF 3157 kb)
Supplementary Information 4
This file contains the Supplementary Character-taxon matrix. (TXT 8 kb)
Rights and permissions
About this article
Cite this article
Longrich, N., Bhullar, BA. & Gauthier, J. A transitional snake from the Late Cretaceous period of North America. Nature 488, 205–208 (2012). https://doi.org/10.1038/nature11227
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature11227
This article is cited by
-
A conserved tooth resorption mechanism in modern and fossil snakes
Nature Communications (2023)
-
First evidence of convergent lifestyle signal in reptile skull roof microanatomy
BMC Biology (2020)
-
The evolution of the axial skeleton intercentrum system in snakes revealed by new data from the Cretaceous snakes Dinilysia and Najash
Scientific Reports (2019)
-
The ecological origins of snakes as revealed by skull evolution
Nature Communications (2018)
-
The origin of snakes: revealing the ecology, behavior, and evolutionary history of early snakes using genomics, phenomics, and the fossil record
BMC Evolutionary Biology (2015)
Comments
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.