Erlang gets a lot of its syntax and implementation technology from Prolog, but it's true that the distinctive things about Erlang (massive shared-nothing concurrency, supervision trees, tuples, pattern-matching on binaries) have nothing in common with the distinctive things about Prolog (backtracking). They both have pattern-matching, but so do lots of other languages (even Python to a small extent).

I'm pretty sure Prolog is still being used, but it doesn't have the buzz of, say, Fortran or COBOL or Pascal.