Once discovered, Anatolian and Tocharian evidence suggested that the original form of the thorn clusters was, in fact, *TK, so that the development outside Anatolian and Tocharian involved a metathesis. The conventional notations *þ *ð *ðʰ for the second elements of these metathesised clusters are still found, and some, including Fortson, continue to hold to the view that interdental fricatives were involved at some stage of PIE. An alternative interpretation (e.g. Vennemann 1989, Schindler 1991 (informally and unpublished)) identifies these segments as alveolar affricates . In this view, thorn clusters developed as TK > TsK > KTs and then variously in daughter languages; this has the advantage that the first change can be identified with the dental assibilation rule above, which is then broadened in application to affrication of dental stops before any stops. Melchert has interpreted the Cuneiform Luwian "īnzagan-" 'inhumation', probably [ind͡zɡan], from * 'in the earth', as preserving the intermediate stage of this process.