Question How do you think fossils form What

Question • How do you think fossils form? • What do you think that fossils tell us?

Fossils • Are preserved remains or traces of living things. • Provide evidence of how life has changed over time.

How fossils form • Most form when living things die and are buried by sediments • Sediments slowly harden into rock and preserve the shapes of the organisms

Sedimentary rock • Fossils usually found in this • Rock is made of hardened sediment.

Found • Most found in animals and plants that lived in or near quiet water such as swamps, lakes, or shallow seas. • Dies = hardens and only hard parts leave fossils

Found • Fossils found in rock include molds and casts, petrified fossils, carbon films, and trace fossils. • Others preserved in tar, amber or ice

Mold • Is a hollow area in sediment in the shape of an organism or part of an organism • Forms when hard part such as a shell is buried in sediment

Cast • Fossil that is a copy of an organisms shape formed when minerals seep into a mold

Petrified fossils • Are fossils in which minerals replace all or part of an organism

Carbon film • Extremely thin coating of carbon on rock

Trace fossils • Provide evidence of the activities of ancient organism. • Ex fossil footprints, trails, and burrows

Paleontologists • Collect and classify fossils

Fossil record • Provides evidence about the history of life on earth • Shows that groups of organisms have changed over time • Shows fossils occur in a particular order

Scientific theory • Well tested concept that explains a wide range of observations

evolution • Is the gradual change in living things over long periods of time • Fossil record shows millions of type of organisms have evolved.

Extinct • No longer exists and will never live on earth again