Underground Tropical Forest Discovered In Illinois

Were people driving SUVs 300,000,000 years ago? Geologists discover world's largest fossil forest in the ceiling of an Illinois coal mine Illinois geologists have discovered the remains of one of the world's oldest tropical rainforests, preserved in the ceiling of a coal mine 250 feet below the surface. The four-square-mile fossil forest — the largest find ever — is just south of Danville in Vermilion County, Ill., in the 300-million-year-old Herrin coal bed, a 6-foot-thick strip mined by a subsidiary of St. Louis-based Peabody Coal. These are the remnants of extinct plants from a geological period 300 million years ago, called the Carboniferous, when the world was covered in a riot of green. Illinois was near the equator and much warmer and wetter.