lone fricatives

Andreas Johansson wrote at 2004-10-12 10:41:52 (+0200)

 >
 > Is there a reason for /s/ being the typical choice of a lone fric?
 > I can't think of any single-fric language where the only fric is
 > anything else than /s/.
 >

I've heard that there is an Australian language of the Warluwarric
family with only /x/ (or maybe /G/?).  Of course, most Australian
languages don't have any fricatives at all.