The taxon is represented by a single family, the Casuariidae, confined to New Guinea and Australia:

Genus-level timetree of extant Casuariiformes following Stiller et al. (2024), with the distribution of each taxon being indicated by the colour-code used throughout this website (Distribution code).

Genus-level classification of extant Casuariiformes.

References

Cloutier A, Sackton TB, Grayson P, Clamp M, Baker AJ, and Edwards SV (2019), Whole-genome analyses resolve the phylogeny of flightless birds (Palaeognathae) in the presence of an empirical anomaly zone, Syst. Biol. 68, 937-955. (abstract)

Sackton TB, Grayson P, Cloutier A, Hu Z, Liu JS, Wheeler NE, Gardner PP, Clarke JA, Baker AJ, Clamp M, and Edwards SV (2019), Convergent regulatory evolution and loss of flight in paleognathous birds. Science 364, 47-78. (link)

Simmons MP, Springer MS, and Gatesy J (2021), Gene-tree misrooting drives conflicts in phylogenomic coalescent analyses of palaeognath birds, Mol. Phylogenet. Evol. 167, e:107344. (abstract)

Smith JV, Braun EL, and Kimball RT (2013), Ratite nonmonophyly: independent evidence from 40 novel loci. Syst. Biol. 62, 35-49. (pdf)

Springer MS, and Gatesy J (2019), Retroposon insertions within a multispecies coalescent framework suggest that ratite phylogeny is not in the 'anomaly zone'. bioRxiv, e:643296. (pdf)

Stiller J, Feng S, Chowdhury AA, Rivas-González I, Duchêne DA, Fang Q, Deng Y, Kozlov A, Stamatakis A, Claramunt S, Nguyen JMT, Ho SYW, Faircloth BC, Haag J, Houde P, Cracraft J, Balaban M, Mai U, Chen G, Gao R, Zhou C, Xie Y, Huang Z, Cao Z, Yan Z, Ogilvie HA, Nakhleh L, Lindow B, Morel B, Fjeldså J, Hosner PA, da Fonseca RR, Petersen B, Tobias JA, Székely T, Kennedy JD, Reeve AH, Liker A, Stervander M, Antunes A, Tietze DT, Bertelsen M, Lei F, Rahbek C, Graves GR, Schierup MH, Warnow T, Braun EL, Gilbert MTP, Jarvis ED, Mirarab S, and Zhang G (2024), Complexity of avian evolution revealed by family-level genomes, Nature 629, 851-860. (preview pdf) 

Takezaki N (2023), Effect of different types of sequence data on palaeognath phylogeny, Genome Biol. Evol. 15, e:evad092. (free pdf)

Urantówka AD, Kroczak A, and Mackiewicz P (2020) New view on the organization and evolution of Palaeognathae mitogenomes poses the question on the ancestral rearrangement in Aves, BMC Genomics 21, e:874. (pdf)

Wang Z, Zhang J, Xu X, Witt C, Deng Y, Chen D, Meng G, Feng S, Szekely T, Zhang G, and Zhou Q (2019), Phylogeny, transposable element and sex chromosome evolution of the basal lineage of birds. BioRxiv. (pdf)

Wang Z, Zhang J, Xu X, Witt C, Deng Y, Chenc G, Meng G, Feng S, Xu L, Szekely T, Zhang G, and Zhou Q (2021), Phylogeny and sex chromosome evolution of Palaeognathae, J Genet. Genomics . (abstract)

Widrig K, and Field DJ (2022), The evolution and fossil record of palaeognathous birds (Neornithes: Palaeognathae), Diversity 14, e:105. (pdf)

Wu S, Rheindt FE, Zhang J, Wang J, Zhang L, Quan C, Li Z, Wang M, Wu F, Qu Y, Edwards SV, Zhou Z, and Liu L (2024), Genomes, fossils, and the concurrent rise of modern birds and flowering plants in the Late Cretaceous, Proc. Natl. Acad. Sci. 121. (pdf)

Yonezawa T, Segawa T, Mori H, Campos PF, Hongoh Y, Endo H, Akiyoshi A, Kohno N, Nishida S, Wu J, Jin H, Adachi J, Kishino H, Kurokawa K, Nogi Y, Tanabe H, Mukoyama H, Yoshida K, Rasoamiaramanana A, Yamagishi S, Hayashi Y, Yoshida A, Koike H, Akishinonomiya F, Willerslev E, and Hasegawa M (2017), Phylogenomics and morphology of extinct paleognaths reveal the origin and evolution of the ratites. Curr. Biol. 27, 68-77. (pdf)