According to Yasugi’s survey of 92 native Middle American languages, /š/ is the second most likely primary fricative. However, this may merely be an areal feature (Yasugi 1995: 68).
Primary fricatives are those speech sounds produced by the narrowing of two articulators so as to produce a turbulent air stream. (This excludes [h]). (Nartey 1979: 3).
Primary fricatives are those speech sounds produced by the narrowing of two articulators so as to produce a turbulent air stream. (This excludes [h]). (Nartey 1979: 3).