The taxon is represented by ~55 species in two families, Galbulidae and Bucconidae. 

Genus-level timetree of extant Galbuliformes based on Witt et al. (2004) and Ferreira (2018). The distribution of each genus is indicated by the colour-code used throughout this website (Distribution code). Interfamiliar divergence times have been adopted from Stiller et al. (2024), who considered two galbuliform genera (Bucco and Galbula). 

Traditional genus-level classification of extant Galbuliformes, following AviList checklist v2025. (link) The number of subspecies is given in parentheses. 

References

Benz BW, Robbins MB, and Peterson AT (2006), Evolutionary history of woodpeckers and allies (Aves: Picidae): placing key taxa on the phylogenetic tree, Mol. Phylogenet. Evol. 40, 389-399. (abstract)

den Tex RJ, and Leonard JA (2013), A molecular phylogeny of Asian barbets: speciation and extiction in the tropics, Mol. Phylogenet. Evol. 68, 1-13. (abstract)

Ericson PGP, Anderson CL, Britton T, Elzanowski A, Johansson US, Källersjö M, Ohlson JI, Parsons TJ, Zuccon D, and Mayr G (2006), Diversification of Neoaves: integration of molecular sequence data and fossils. Biol. Lett. 2, 543-547. (abstract)

Ferreira M (2018), "Filogenia e biogeografia de tres famílias de aves do Neotrópico", Ph.D. dissertation, INPA Manaus. (free pdf)

Ferreira M, Aleixo A, Ribas CC, and Santos MPD (2017), Biogeography of the Neotropical genus Malacoptila (Aves: Bucconidae): the influence of the Andean orogeny, Amazonian drainage evolution and palaeoclimate, J. Biogeogr. 44, 748-759. (abstract)

Johansson US, and Ericson PGP (2003), Molecular support for a sister group relationship between Pici and Galbulae (Piciformes sensu Wetmore 1960), J. Avian Biol. 34, 185-197. (abstract)

Kuhl H, Frankl-Vilches C, Bakker A, Mayr G, Nikolaus G, Boerno ST, Klages S, Timmermann B, and Gahr M (2021), An unbiased molecular approach using 3'UTRs resolves the avian family-level tree of life, Mol. Biol. Evol. 38, 108-127. (free pdf)

Moyle RG (2004), Phylogenetics of barbets (Aves: Piciformes) based on nuclear and mitochondrial DNA sequence data, Mol. Phylogenet. Evol. 30, 187-200. (abstract)

Navarro-Sigüenza AG, Vázquez-Miranda H, Hernández-Alonso G, García-Trejo EA, and Sánchez-González LA (2017), Complex biogeographic scenarios revealed in the diversification of the largest woodpecker radiation in the New World, Mol. Phylogenet. Evol. 112, 53-67. (abstract) 

Ogolowa BO, Brelsford A, Fjeldså J, Fulgione A, Hadjioannou L, Henderson EC, Moyle RG, Moysi M, Nwankwo EC, Rancilhac L, Smith TB, von Holdt BM, and Kirschel ANG (2025), Plio-Pleistocene climatic fluctuations and divergence with gene flow drive continent-wide diversification in an African bird, Mol. Evol. 34, e:17770. (pdf)

Ostrow EN, Catanach TA, Bates JM, Aleixo A, and Weckstein JD (2023), Phylogenomic analysis confirms the relationships among toucans, toucan-barbets, and New World barbets but reveals paraphyly of Selenidera toucanets and evidence for mitonuclear discordance, Ornithology 140, e:ukad022. (free pdf)

Shakya SB, Fuchs J, Pons JM, and Sheldon FH (2017), Tapping the woodpecker tree for evolutionary insight, Mol. Phylogenet. Evol. 116, 182-191. (abstract)

Tamashiro RA, White NE, Braun MJ, Faircloth BC, Braun EL, and Kimball RE (2019), What are the roles of taxon sampling and model fit in tests of cyto-nuclear discordance using avian mitogenomic data?, Mol. Phylogenet. Evol. 130, 132-144. (abstract)

Webb DM, and Moore (2005), A phylogenetic analysis of woodpeckers and their allies using 12S, Cyt b, and COI nucleotide sequences (class Aves; order Piciformes), Mol. Phylogenet. Evol. 36, 233-248. (abstract)

Witt CC (2004), “Rates of molecular evolution and their application to neotropical avian biogeography”, Ph.D. dissertation, Louisiana State University. (pdf)