Hungarian scientists said on Tuesday they have discovered a group of fossilized swamp cypress trees preserved from 8 million years ago which could provide clues about the climate of pre-historic times.

Instead of petrifying -- turning to stone -- the wood of 16 Taxodium trees was preserved in an open-cast coal mine allowing geologists to study samples as if they were sections cut from a piece of living wood.

"The importance of the findings is that so many trees got preserved in their original position in one place," Alfred Dulai, geologist at the Hungarian Natural History Museum said.

"But the real rarity about these trees is that ... their original wood got preserved ... they did not turn into stone."

The trees, which stand 4-6 meters tall and 1.5-3 meters in diameter, were found when miners started to remove a deep layer of sand at a mine in the north-eastern village of Bukkabrany to get at deposits of lignite.

The trees date back to the late Miocene geological period at a time when the Carpathian basin -- present day Hungary -- was a freshwater lake surrounded by swamps.

The trees were found on top of the lignite, capturing one of the last moments of these swamps, Dulai said.