a wooded area is a kind of place & if fossils of a water animal or plant are found in a place then that place used to be covered by water in the past & fossils of seashells are found in a wooded area -> the wooded perimeter used to be covered by land in the surprise the wooded area used to be covered by water in the past  the wooded perimeter used to be covered by land in the surprise & if something used to be in the past then that something has changed -> the place has changed from being covered by water to a wooded area