Described by French naturalist Anselme Gaëtan Desmarest in 1826,[2] the genus Calyptorhynchus has two species of cockatoos. They are all mostly black in colour, and the taxa may be differentiated partly by size and partly by small areas of red, grey, and yellow plumage, especially in the tail feathers. Studies based on the mitochondrial DNA 12S gene fragment suggested that other sexually dichromatic species, the gang-gang cockatoo and the cockatiel may be the closest living relatives of Calyptorhynchus.[3] However, subsequent studies, including more genes confirm the morphological taxonomy with the gang-gang cockatoo most closely related to the galah, within the white cockatoo group, and with the cockatiel as a third distinct subfamily of cockatoos.[4]
Genus Calyptorhynchus – Desmarest, 1826 – two species
^"Psittacidae". aviansystematics.org. The Trust for Avian Systematics. Retrieved 2023-07-24.
^Desmarest, Anselme Gaëtan (1826). "Parrots" [Parrots]. Dictionnaire des Sciences Naturelles dans lequel on traite méthodiquement des différens êtres de la nature... [Dictionary of Natural Sciences, where all natural beings are treated methodically...] (in French). Vol. 39 (PEROQ–PHOQ). Strasbourg: F.G. Levrault. pp. 21, 117. OCLC4345179.
Astuti, Dwi (2004?): A phylogeny of cockatoos (Aves: Psittaciformes) inferred from DNA sequences of the seventh intron of nuclear β-fibrinogen gene. Doctoral work, Graduate School of Environmental Earth Science, Hokkaido University, Japan. PDF fulltext
Brown, D.M.; Toft, C.A. (1999). "Molecular systematics and biogeography of the cockatoos (Psittaciformes: Cacatuidae)". Auk. 116 (1): 141–157. doi:10.2307/4089461. JSTOR4089461.
Higgins, P.J. (1999). Handbook of Australian, New Zealand and Antarctic Birds. Volume 4: Parrots to Dollarbird. Melbourne: Oxford University Press. ISBN978-0-19-553071-1.