Subterranean Fossilized Forest

Miners working in two neighboring Illinois coal mines have made one of the most astounding discoveries of the 21st century. As they dug deep beneath the earth, they began to notice that the ceilings of their tunnels displayed an astounding variety of plant fossils, including 130-foot club mosses and tree-sized horsetails that resembled giant asparagus. As it turns out, they had unwittingly uncovered the remains of one of the planet's first rain forests.

Scientists estimate that the forest was buried by an earthquake around 300 million years ago. Thousands of extinct species were preserved in exquisite detail. Today, the fossil forest rests more than three hundred feet below the surface and extends over forty square miles. (An area roughly the same size as San Francisco.)

Read more here.

(Below: One of the fossils.)