The inland thornbill (Acanthiza apicalis) was originally described by English ornithologist John Gould in The Birds of Australia. Inland thornbills are within the order passerines. The inland thornbill belongs to the genus Acanthiza, which now has three more species than the eleven outlined by Gould in The Birds of Australia. The Noongar people of southwestern Western Australia call A. apicalis "Djoobi-Djoolbang". The inland thornbill is also known as the broad-tail thornbill and presently contains several subspecies that were once considered independent species. The word apicalis comes from the Latin for 'tipped'. Taxonomy and evolution Early classification of the Acanthiza, or thornbill genus, was inconsistent with the currently accepted taxonomy. Historically, researchers recognised 10 -17 species in 1 – 3 genera. Separate traditional species of Thornbill have now been more accurately classified as subspecies than discrete species; however, the evolutionary relationships between inland thornbills and other Acanthizae are complicated. For example, the relationship between the inland thornbill and the brown thornbill (A. pusilla) and the mountain thornbill (A. katherina) is more complex than just classifying the genus. To further complicate the evolutionary relationships between species in the genus Acanthiza, two species exist outside of Australia in New Guinea. The New Guinea thornbill (A. murina) is found in the highlands of New Guinea, and it is not definitive how this species fits in with the classification of other thornbills. Still, some research has found the New Guinea thornbill to be closely related to A.nana or the yellow thornbill. Traditionally Acanthiza classification was conducted using morphology and plumage patterns. Recent research using base-substitution data from nuclear DNA (nDNA) sequences sampled from Acanthiza species identified five separate species groups. Inland thornbills are in the same species group as A, pusilla, A. ewingii, and A. katherina. The other species groups are one containing A. inornate, A. uropygialis, A, reguloides, and A. iredalei, one containing A. nana and A. lineata, one containing A. chrysorrhoa, and one for A. robustirostris. The results of the Acanthizae nDNA samples were compared to samples from the gerygone, whiteface and weebill genera, as these species have previously been found to be in the same tribe as Acanthiza. Subspecies There are four recognised subspecies of inland thornbill with different geographic regions: Acanthiza apicalis apicalis: the nominate subspecies. Southwestern Western Australia Acanthiza apicalis albiventris: Eastern South Australia and northwestern Victoria; central New South Wales and Queensland. Acanthiza apicalis cinerascens: West-central Queensland Acanthiza apicalis