premise: A 300 million-year-old fossilized rain forest has been found, in its entirety, outside Georgetown, Illinois, United States. Coal miners called in scientists to look at a vast and dense seam of fossils they found in a mine. It is the largest fossilized forest ever to be found. It is about the size of San Francisco, California or 10,000 hectares [10 km by 10 km] and is said to be the first rain forest ever to exist on Earth.
hypothesis: Fossilized trees have been found in the USA.