EXTREME LIFE form

[RonButters at AOL.COM]

I came across the phrase EXTREME LIFE in today's DURHAM MORNING HERALD (1/17/
02, pA7/1&3); not sure from the context if it is a nonce form, a mistake, or
some established form that I knew nothing about before:

<<Scientists ... have discovered a unique community of microbes that thrive
without sunlight or oxygen. ... In the light of the findings, researchers
said the question should no longer be whether extreme life exists on Mars and
elsewhere.>>

The article refers to a an article published today in the journal NATURE.