Scientists and coal miners have discovered a huge fossilised forest that existed tens of millions of years before the dinosaurs.

Located in the depths of an Illinois coal mine in the United States, explorers believe the beautifully preserved remnants of this ancient ecosystem extends for more than 100 miles, at least 50 times bigger than previous discoveries.

The forest is believed to have been wiped out by flooding caused by global warming. 

 "A river as wide as the Mississippi snaked through the fossil-forest landscape; its course is still clearly visible," writes W. Barksdale Maynard in The New York Times. "As the climate grew drier with rising temperatures in the late Carboniferous period, rainfall became seasonal and pounded sediment out of the soil, filling the river with silt. This suffocated the forest as the river spilled over its banks. The flooding was incremental and gradual, hardly ruffling the fern leaves that it entombed in mud and that can be seen, down to the smallest frond, on the ceilings of the coal mines. Huge fossilized trees still stand rooted in their original but compacted soil, surrounded by the litter of leaves that once fluttered down."

The vast extent of this find will allow scientists to undertake ecosystem-wide analyses in a way never before possible in landscapes so ancient.

And the results could provide clues on just how modern climate change will affect our environment.

Take a look meanwhile at photos published by the Illinois State Geological Survey of a similar, but much smaller, fossilised forest in the Herrin Coal Mine.  The geologic team is the same one exploring the new discovery.

Howard Falcon-Lang and John Nelson stand below a fossilised tree trunk in the Herrin Coal Mine. The fossil is nearly 2 meters wide and 30 meters long; the actual tree was even bigger. Images by Howard Falcon-Lang, Bill DiMichele and Scott Elrick.