ABSTRACT The origin of extant amphibians (Lissamphibia: frogs, salamanders and caecilians) is one of the most controversial questions in vertebrate evolution, owing to large morphological

and temporal gaps in the fossil record1,2,3. Current discussions focus on three competing hypotheses: a monophyletic origin within either Temnospondyli4,5,6,7 or Lepospondyli8,9,10, or a

polyphyletic origin with frogs and salamanders arising among temnospondyls and caecilians among the lepospondyls11,12,13,14,15,16. Recent molecular analyses are also controversial, with

estimations for the batrachian (frog–salamander) divergence significantly older than the palaeontological evidence supports17,18. Here we report the discovery of an amphibamid temnospondyl

divergence occurred in the Middle Permian, rather than the late Carboniferous as recently estimated using molecular clocks18,22, but the divergence with caecilians corresponds to the deep

split between temnospondyls and lepospondyls, which is congruent with the molecular estimates. Access through your institution Buy or subscribe This is a preview of subscription content,

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ORIGIN OF LIVING AMPHIBIANS Article Open access 25 January 2023 A NEW AVIALAN THEROPOD FROM AN EMERGING JURASSIC TERRESTRIAL FAUNA Article 06 September 2023 _CONGOLIUS_, A NEW GENUS OF

AFRICAN REED FROG ENDEMIC TO THE CENTRAL CONGO: A POTENTIAL CASE OF CONVERGENT EVOLUTION Article Open access 16 April 2021 REFERENCES * Milner, A. R. in _The Phylogeny and Classification of

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modern amphibians. _Mol. Phylogenet. Evol._ 40, 635–639 (2006) Article  CAS  Google Scholar  Download references ACKNOWLEDGEMENTS We thank M. Carrano, D. Chaney, B. DiMichele and P. Kroehler

of the USNM for information and photographs of the discovery locality and for access to the specimen. E. Rega transported the specimen from Washington DC to Los Angeles. We thank P. Janvier

and le Museum National d’Histoire Naturelle in Paris for support while one of us (J.S.A.) studied the holotype of _Triadobatrachus_. The research was further supported by Natural Science

and Engineering Research Council of Canada Discovery Grants to R.R.R. and J.S.A. AUTHOR CONTRIBUTIONS J.S.A. contributed to project planning, figure preparation, anatomical analysis,

phylogenetic analysis, manuscript preparation and financial support for study; R.R.R. to phylogenetic analysis, manuscript preparation and financial support; D.S. to specimen preparation,

figure preparation, anatomical analysis and manuscript preparation; N.B.F. to anatomical analysis, phylogenetic analysis and manuscript preparation; and S.S.S. to project initiation and

manuscript preparation. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330

Hospital Drive, Calgary, Alberta T2N 4N1, Canada, Jason S. Anderson * Department of Biology, University of Toronto at Mississauga, 3359 Mississauga Road, Mississauga, Ontario L5L 1C6,

Canada, Robert R. Reisz & Diane Scott * Redpath Museum, McGill University, 859 Sherbrooke Street West, Montréal, Québec H3A 2K6, Canada , Nadia B. Fröbisch * Department of Biology,

California State University at San Bernardino, 5500 University Parkway, San Bernardino, California 92407-2307, USA, Stuart S. Sumida Authors * Jason S. Anderson View author publications You

can also search for this author inPubMed Google Scholar * Robert R. Reisz View author publications You can also search for this author inPubMed Google Scholar * Diane Scott View author

publications You can also search for this author inPubMed Google Scholar * Nadia B. Fröbisch View author publications You can also search for this author inPubMed Google Scholar * Stuart S.

Sumida View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING AUTHOR Correspondence to Jason S. Anderson. SUPPLEMENTARY INFORMATION SUPPLEMENTARY

INFORMATION The file contains Supplementary Data including the data matrix in Nexsus format saved in Rich Text. (RTF 44 kb) RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE

CITE THIS ARTICLE Anderson, J., Reisz, R., Scott, D. _et al._ A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders. _Nature_ 453, 515–518 (2008).

https://doi.org/10.1038/nature06865 Download citation * Received: 23 October 2007 * Accepted: 25 February 2008 * Issue Date: 22 May 2008 * DOI: https://doi.org/10.1038/nature06865 SHARE THIS

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