Ray Brown wrote:

> I can think of languages that have /s/ but no other fricatives; but I
> cannot think of any with just /T/. However, I don't see why at some stage
> a lonely [s] could not have changed to [T]....
> fact I would not be unduly surprised if a language were
> found with /T/ as its only fricative.

IIRC you or someone else mentioned Burmese, which has [T] reflecting *s; it
may also have [s] from some other source, but I don't know.

Apparently [T] is an acceptable pronunciation of /s/ in Acehnese, and
characterizes at least one dialect thereof.

Fijian has /D/ [D], also reflecting *s (and others), but no [T]~/T/; but
also /s/ reflecting other proto-sounds. It also boasts /v/ [B], but no /f/.
(Fijian /v/ reflects earlier *f.)

Hawaiian has the sole fricative /h/, which is the merger of the same two
earlier sounds, *f and *s.

ObConlang: Proto-Kash had no *s at all; it did have *th and *ts, which
developed to /s/ in many descendants. A major violation I suppose, but then
they're aliens, and our "universals" may be quite -centric, and aren't
necessarily Universal.