The phylogenetic tree presented here is a consensus assembled by hand from recent sources (see below) and represents the best estimate of evolutionary relationships in the expert opinion of The AmphibiaWeb Team as of January 2019. The first version of the AmphibiaWeb phylogeny originated from the summary provided by Blackburn and Wake (2011) based on their evaluation of the literature available at that time. Additional resolution and some minor changes result from more recent studies that include additional taxa and more extensive data sets, especially nuclear-coding DNA sequences from across the genome. Especially important are the data-rich publications by Feng et al. (2017), Streicher et al. (2018), and Yuan et al. (2018). However, relationships remain unresolved among important families due to uncertainty in individual studies or strong conflict among studies. This includes, for example, the polytomy involving the Bufonidae, Leptodactylidae, Dendrobatidae, and terraranan frogs (e.g., Eleutherodactylidae), as well as the polytomy of Ceratophryidae, Hemiphractidae, and Hylidae.
Jetz and Pyron (2018) presented a tree with the greatest number of amphibian species (4061) based on 5 mitochondrial and 10 nuclear gene sequences, but not including those of Feng et al. (2017), Streicher et al. (2018), or Yuan et al. (2018), and they extrapolated it to 7238 species. It is useful for placing individual species in phylogenetic context, though has strong conflict with higher-level relationships based on more extensive sampling of the genome from other recent studies.
Blackburn, D. C., and D. B. Wake. 2011. Class Amphibia Gray, 1825. Zhang, Z.-q. ed., Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness. Zootaxa 3148: 39–55 (PDF).
Feng , Y-L, D. C. Blackburn, D. Liang, D. M. Hillis, D. B. Wake, D. C. Cannatella, and P. Zhang. 2017. Phylogenomics reveals rapid, simultaneous diversification three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary. Proceedings of the National Academy of Sciences.
Jetz, W, and R. A. Pyron. 2018. The interplay of past diversification and evolutionary isolation with present imperilment across the amphibian tree of life. Nature Ecology & Evolution 2:850-858.
Streicher, J.W., E.C. Miller, P.C. Guerrero, C. Correa, J.C. Ortiz, A.J. Crawford, M.R. Pie, and J.J. Wiens. 2018. Evaluating methods for phylogenomic analyses, and a new phylogeny for a major frog clade (Hyloidea) based on 2214 loci. Molecular Phylogenetics and Evolution 119: 128–143.
Yuan, Z.-Y., B.-L. Zhang, C.J. Raxworthy, D.W. Weisrock, P.M. Hime, J.-Q. Jin, E.M. Lemmon, A.R. Lemmon, S.D. Holland, M.K. Kortyna, W.-W. Zhou, M.-S. Peng, J. Che, and E. Prendini. 2018. Natatanuran frogs used the Indian Plate to step-stone disperse and radiate across the Indian Ocean. National Science Review, nw092.
Heinicke, M.P., A.R. Lemmon, E.M. Lemmon, K. McGrath, and S.B. Hedges. 2018. Phylogenomic support for evolutionary relationships of New World direct-developing frogs (Anura: Terraranae). Molecular Phylogenetics and Evolution 118: 145–155.
Yan, F., K. Jiang, K. Wang, J.-Q. Jin, C. Suwannapoom, C. Li, J.V. Vindum, R.M. Brown, and J. Che. 2016. The Australasian frog family Certatophryidae in China, Myanmar and Thailand: discovery of a new Himalayan forest frog clade. Zoological Research 37: 7–14.