Excerpt from change request document:
Nauo, also known as Nawo, is a poorly attested, but clearly separate language from Wirangu (ISO 639-3: wiw). Ethnologue 16 currently lists "Nhawu" as an alternate name of Wirangu, but this name actually refers to this separate language Nauo. Hercus and Simpson investigated the little that is known about Nauo in their article "The Tragedy of Nauo," arguing that "the Nauo people were part of a chain of culturally related groups living on Eyre Peninsula and along the west coast, and that their language had elements in common with both Wirangu and Barngarla" (2001: 263).
Hercus and Simpson also argue that Wirangu is not a dialect of the Western Desert language, but is in fact a member of the Thura-Yura subgroup (2004). Hercus and Simpson systematically show that Nauo is a Thura-Yura language in their 2001 article, demonstrating that it has some qualities that are similar to Wirangu and others that are similar to Barnggarla (ISO 639-3: bjb). They explain that "phonotactically, it resembles Wirangu, rather than Barngarla, in allowing initial 'ty(i)' , and 'i-u' sequences. Three distinctive Nauo properties are the morphemes '-yu' and '-lye', and the final vowel of the second person singular, 'niino'. Finally, Schürmann's observation that Nauo was vowel-final is important: this links it with Barngarla and distinguishes it from Wirangu, Mirniny, and Kukata" (2001: 279).
As far back as 1966, O'Grady, Voegelin and Voegelin included Nawu in their Yura subgroup (40). Wirangu was included in a separate subgroup called Nangga (1966: 40). More recently, Tryon has classified both Wirangu and what he calls Nawu as Thura-Yura languages (2007: 117).
AUSTLANG follows both Hercus and Simpson 2001 and 2004 and places both Wirangu and Nauo in the Thura-Yura subgroup of the Pama-Nyungan family (2011).
It should also be noted that Hercus and Simpson 2004 identified two dialects of Wirangu, Modern Wirangu and Gawler Ranges Wirangu (181, 182-183).