• Traces or remains of living things Traces or remains of living things from long ago.from long ago.

• There are 2 main types of fossils:There are 2 main types of fossils:

1.1. Original remainsOriginal remains

2.2. Rock fossilsRock fossils

• Fossils that are the actual bodies Fossils that are the actual bodies or body parts of organisms.or body parts of organisms.

• There are 3 modes of preservation:There are 3 modes of preservation:

1.1. IceIce

2.2. AmberAmber

3.3. TarTar

• Ice is one of the best preservers of the Ice is one of the best preservers of the remains of prehistoric life.remains of prehistoric life.

• Huge ice fields in Siberia and Alaska Huge ice fields in Siberia and Alaska contain 10,000 year-old mammoths.contain 10,000 year-old mammoths.

• Amber forms from resin, a sticky Amber forms from resin, a sticky substance inside trees that flows like substance inside trees that flows like syrup and protects the tree by trapping syrup and protects the tree by trapping insects.insects.

• Original remains of animals have also Original remains of animals have also been found in places where there are been found in places where there are pools of tar – a thick, oily substance.pools of tar – a thick, oily substance.

• If an organism is covered by or If an organism is covered by or buried in sediment, it may buried in sediment, it may become a fossil as the sediments become a fossil as the sediments become rock.become rock.

• There are 4 main types of fossils There are 4 main types of fossils that we find in rocks: molds and that we find in rocks: molds and casts, petrified wood, carbon casts, petrified wood, carbon films and trace fossilsfilms and trace fossils

• A mold is a visible shape A mold is a visible shape that has left after an animal that has left after an animal or plant was buried in or plant was buried in sediment and then decayed sediment and then decayed away.away.

• A cast fossil is a solid model A cast fossil is a solid model in the shape of the in the shape of the organism.organism.

• The stone fossil of a tree is called The stone fossil of a tree is called petrified wood.petrified wood.

• Carbon is an element Carbon is an element that is found in every that is found in every living thing.living thing.

• Sometimes when a Sometimes when a dead plant or animal dead plant or animal decays, its carbon is decays, its carbon is left behind as a left behind as a visible layer.visible layer.

• Trace fossils are not parts Trace fossils are not parts of an animal or of an animal or impressions of it, but impressions of it, but rather evidence of an rather evidence of an animal’s presence in a animal’s presence in a given location.given location.

• Trace fossils include: Trace fossils include: footprints, trails, animal footprints, trails, animal holes, and even feces.holes, and even feces.

• Conditions have to be just right for Conditions have to be just right for a fossil to form in rock – the a fossil to form in rock – the organism must be preserved organism must be preserved before it decomposes or before it decomposes or disappears.disappears.

• Rock fossils form in sedimentary Rock fossils form in sedimentary rock. Why not in igneous rocks?rock. Why not in igneous rocks?