The discovery shows for the first time that plant life has the ability to survive millennial-scale ice ages.
Mosses are key players in the ecosystems of northern and southern polar regions and are the dominant plants across large areas.
They have been known to survive extreme environments for up to 20 years.
Professor Peter Convey, from the British Antarctic Survey (BAS), said: "What mosses do in the ecosystem is far more important than we would generally realise when we look at a moss on a wall here for instance.
"Understanding what controls their growth and distribution, particularly in a fast-changing part of the world such as the Antarctic Peninsula region, is therefore of much wider significance."
The BAS team worked with colleagues from the University of Reading.