Fossils
preserved remains or traces of living things. They provide evidence of how life has changed over time
Petrified fossils
remains of an organism become petrified, or turned into stone.
Sedimentary rock
type of rock that is made of hardened sediment
sediment
earth materials deposited by erosion
mold
is a hollow area in sediment in the shape of an organism or part of the organism. Mold forms when the hard part of the organism such as a shell, is buried in sediment
Cast
A cast is a fossil that is a copy of an organism's shape formed when minerals seep into a mold. Both the mold and the cast preserve the details of the animal's structure
Carbon Films
A type of fossil consisting of an extremely thin coating of carbon on rock.
Trace fossils
A type of fossil that provides evidence of the activities of ancient organisms. A fossilized footprint is one example of a trace fossils.
Scientific theory
is a well-tested concept that explains a wide range of observations.
Evolution
is a gradual change in living things over long periods of time.
Extinct
Means that a type of organism no longer exists and will never again live on earth