(jump down one level to Limaish)
Pituish has two branches: Favorlang-Taokas (here) and Limaish (here). It is defined by the innovation of *pitu ‘seven’, as discussed in Sagart (2004) (here), to which readers are referred. *pitu replaces PAN *RaCep-i-tuSa ‘five-plus-two: seven’, of which it is a left- and right-pruned form: *pitu < *(
In addition, a non-displacing innovation in Pituish created a new numeral for ‘nine’, based on *sa-ŋ-aCu ‘one taken away’ (from ‘ten’): Favorlang tannacho, Babuza #131 tanahu,Taokas tanasu, Thao: tanacu. It is listed as cognate set #6 in the ABVD (here). All through Limaish and Enemish, the new numeral competed with the inherited *RaCep-i-Sepat ‘five plus four’ found in Pazeh xaseb-i-supat. It did not displace it either in Limaish or in Enemish, since later *Siwa, simplified from *RaCep-i-Sepat, finally displaces all its competitors in Walu-Siwaish. *sa-ŋ-aCu ‘9’ does not appear in the other Pituish languages upstream of Proto-Walu-Siwaish, because of a series of local innovations displacing *sa-ŋ-aCu: Atayal qeru, Sediq maŋali, and in Siraya matauda.
Sagart, L. (2004) The higher phylogeny of Austronesian and the position of Tai-Kadai. Oceanic Linguistics 43,2: 411-444.