plural of mold fossil

plural of cast fossil

plural of trace fossil

plural of living fossil

plural of body fossil

A fossil formed when sediment fills the inside or covers the outside of a dead organism and the organism's remains do not persist, leaving just the shape and texture of the rock to indicate the organic material that was there.

crude oil

Water that has remained in an aquifer for a long timespan, usually thousands or millions of years.

A fossil formed when an animal, plant, or other organism dies, its flesh decays and bones deteriorate due to chemical reactions; minerals gradually enter into the cavity, resulting in a cast, which is in the general form of the original organism.

Any fuel derived from hydrocarbon deposits such as coal, petroleum, natural gas and, to some extent, peat; these fuels are non-renewable, and their burning generates the greenhouse gas carbon dioxide.