George Robert Gray described the Norfolk parakeet in 1859 as
Platycercus Cookii, from a specimen in
William Bullock's museum, and recorded it as from New Zealand. The species name honours
James Cook, who reported the species on Norfolk Island when he landed there in 1774, noting it was the same as those occurring in New Zealand. In 1862, Gray described a specimen from Norfolk Island as
Platycercus rayneri, collected by a Mr Rayner. In 1891, Italian ornithologist
Tommaso Salvadori confirmed the two taxa as
synonymous and coming from Norfolk Island. It was long considered a subspecies of the
red-fronted parakeet of
New Zealand. Ornithologists
Alfred North (1893) and Graeme Phipps (1981) noted that the Norfolk parakeet was significantly larger than the red-fronted parakeet. Phipps added that further investigation was needed into their status and conservation. DNA analysis in 2001 showed that it was an early offshoot from the other parakeets in the genus
Cyanoramphus, with only the
New Caledonian and
Chatham parakeet more divergent. "Norfolk parakeet" has been designated the official name by the
International Ornithologists' Union (IOC). It is also known as Norfolk Island green parrot, The name "Tasman parakeet" is used by ornithologists
Les Christidis and
Walter Boles on the argument that this species and the
Lord Howe red-crowned parakeet (
Cyanoramphus novaezelandiae subflavescens) are probably a single species for which they use biogeographical arguments. Tasman is used for other species with the same distribution and they propose that name for that reason. However, the latter subspecies was not included in the genus-wide phylogenetic reconstruction using DNA sequences, and the lumping of the species should be considered tentative. ==Distribution and habitat==