Discovered in fluid-filled cracks in a South African gold mine, a new microbial life form is capable of sustaining its existence in the complete absence of light or oxygen:

http://environment.newscientist.com/article/dn14906-goldmine-bug-dna-may-be-key-to-alien-life.html

Scientists hope that by studying the creature, new insight may be obtained as to how life could exist elsewhere in isolated parts of the universe.