[[Image:Polystrate tree.gif|thumb|right|200px250px|Drawing of a tree, fossilized upright]]
'''Polystrate fossils''' are fossils which occupy or span through more than one strata of rock. They are usually trees, and whole polystrate fossil forests have been found in various places. Rarely, they are fossilized bones. They are used by [[young Earth creationists]] as evidence against the [[Uniformitarianism|uniformitarian]] timescale.