Fossils!

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

Fossils

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 organism’s 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 types of organisms have evolved.

Extinct No longer exists and will never live on earth again

Extinction