The origin of modern amphibians: a re-evaluation
Article first published online: 21 JAN 2011
© 2011 The Linnean Society of London
Zoological Journal of the Linnean Society
Volume 162, Issue 2, pages 457–469, June 2011
How to Cite
SIGURDSEN, T. and GREEN, D. M. (2011), The origin of modern amphibians: a re-evaluation. Zoological Journal of the Linnean Society, 162: 457–469. doi: 10.1111/j.1096-3642.2010.00683.x
- Issue published online: 27 MAY 2011
- Article first published online: 21 JAN 2011
- Received 23 March 2010; revised 17 June 2010; accepted for publication 21 June 2010
There are currently three competing hypotheses seeking to explain the evolutionary origins of modern amphibians. The lepospondyl hypothesis holds that the lysorophian lepospondyls constitute the sister taxon to all lissamphibians. The temnospondyl hypothesis suggests that modern amphibians are most closely related to the dissorophoid temnospondyls. Finally, the polyphyletic hypothesis posits that the modern amphibian orders have separate evolutionary origins from among different groups of Palaeozoic tetrapods. Here, we review the character matrices used in previous studies. These data sets differ significantly in choice of characters. Therefore, we built a matrix based on data from all three hypotheses and analysed key taxa phylogenetically using both Bayesian inference and parsimony. Uncorrected, the supermatrix yielded inconclusive results, demonstrating the presence of at least two phylogenetic optima. When the data were corrected according to new observations on Doleserpeton, Eocaecilia, and other fossil forms, the phylogeny supported the temnospondyl hypothesis of lissamphibian origins. This conclusion is also supported by a careful study of character changes in the individual lineages.
© 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162, 457–469.