As well as the eucalypts, the Greater Blue Mountains Area also contains ancient, relict species of world wide importance. The most famous of these is the recently discovered Wollemi pine. This tree is a "living fossil" dating back to the age of the dinosaurs. Thought to have been extinct for millions of years, the few surviving trees of this ancient species are known only from three small groups located in remote valleys within the area. The Wollemi pine is one of the world's rarest species.