A TRIP THROUGH GEOLOGIC TIME Fossils Fossils are

*Fossils are preserved remains or traces of living things. *Most fossils form when living

*Fossils are usually found in sedimentary rocks. *When an organism dies, its soft parts

*PETRIFIED FOSSILS *KINDS OF FOSSILS. *Fossils where minerals replace all or part of the

*MOLDS AND CASTS * A mold is a hollow area in sediment in the

*CARBON FILM FOSSILS. *KINDS OF FOSSILS. *Carbon films are extremely thin coatings of carbon

* TRACE FOSSILS. *KINDS OF FOSSILS. *Trace Fossils provide evidence of the activities of

* PRESERVED REMAINS. *Preserved Remains are formed when an organism is preserved with little

*WHY STUDY FOSSILS? *To learn what *To classify past life forms organisms in the

*WHY STUDY FOSSILS? *All the information scientists have gathered is called the fossil record.

*INDEX FOSSILS. *They *Scientists use index fossils to match rock layers. *MUST BE WIDELY

*INDEX FOSSIL-THE TRILOBITE. *A group of hard –shelled animals whose bodies had three distinct

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A TRIP THROUGH GEOLOGIC TIME: Fossils

*Fossils are preserved remains or traces of living things. *Most fossils form when living things are buried by sediments. *These slowly harden into rock and preserve the shape of the organism. *Scientists that study fossils are paleontologists.

*Fossils are usually found in sedimentary rocks. *When an organism dies, its soft parts often decay quickly, leaving only the hard parts to fossilize. *Ex: Bones, Shells, Teeth, or Seeds.

*PETRIFIED FOSSILS *KINDS OF FOSSILS. *Fossils where minerals replace all or part of the organism. ie: Petrified Wood *When the object is buried by sediment, water rich in minerals seeps into its cells; when the water evaporates, the minerals are left behind.

*MOLDS AND CASTS * A mold is a hollow area in sediment in the shape of an organism or part of an organism. *A cast is a copy of the shape of the organism. *KINDS OF FOSSILS. http: //www. classzone. com/boo ks/earth_science/terc/content/ visualizations/es 2901 p age 01. cfm

*CARBON FILM FOSSILS. *KINDS OF FOSSILS. *Carbon films are extremely thin coatings of carbon on rock that form when materials that make up an organism become gases and escape leaving only Carbon behind.

* TRACE FOSSILS. *KINDS OF FOSSILS. *Trace Fossils provide evidence of the activities of ancient organisms. For example – footprints, animal trails, or animal burrows

* PRESERVED REMAINS. *Preserved Remains are formed when an organism is preserved with little or no change *KINDS OF FOSSILS. For example when organism become trapped and preserved in tar, amber (tree sap), or ice

*WHY STUDY FOSSILS? *To learn what *To classify past life forms organisms in the order in which were like they lived *To prove extinct species existed!

*WHY STUDY FOSSILS? *All the information scientists have gathered is called the fossil record. *Shows how groups of organisms have changed over time. * Helps support the Theory of Evolution

One last thing… INDEX FOSSILS

*INDEX FOSSILS. *They *Scientists use index fossils to match rock layers. *MUST BE WIDELY DISTRIBUTED (spread out) and ONLY EXISTED BRIEFLY. are useful because they tell the relative ages of the rock layers they are found in.

*INDEX FOSSIL-THE TRILOBITE. *A group of hard –shelled animals whose bodies had three distinct parts. *Evolved more than 500 million years ago.