While preparing data from a sample of Native American languages for mass lexical comparison, I noticed a curious feature of the phonology of these languages. We normally expect tone to occur on vowels, but a large number of the languages in the sample contained consonants marked for tone. It was always the same four consonants on which tonal marking occurred
Since this curious feature is found throughout the Americas, it must have been present in the language of the first inhabitants of the continent, and understanding its origin will tell us something important about Proto-
i → j is a common enough sound change, but we would normally expect it to neutralize tonal distinctions. However, there must have been some context in which the contrast between ǐ and other tones was so salient that the distinction was preserved, thus giving rise to ǰ. Professors Thanneven and Lemma-
There is a conspicuous gap in the consonants produced by this mechanism. We might expect tǰ → t͜ʃ̌ → tˇ, dǰ → d͜ǯ → dˇ, nǰ → ɲ̌ → ň, but these are nowhere seen. Whether these consonants resisted palatalisation or whether they later lost the tonal contrast is a matter for further research.
Another peculiar consonant that occurs in many of these languages is ñ. Unfortunately, since my fixed term contract is coming to an end (and didn’t turn out to be self-