FOSSILS Essential Questions: What are fossils and how are they formed? What are the different kinds of fossils? What do fossils tell about how organisms have changed over time? How do we determine the age of fossils?

Dinosaur Fossil Phenomenon How were these fossils made? What could they tell us about life’s history?

Fossils Fossils are the preserved remains or traces of living things. provide evidence of how life has changed over time. help scientists infer how Earth’s surface has changed. are clues to what past environments were like.

TYPES OF FOSSILS Permineralization- minerals carried by water are deposited around or replace the hard structure Casts- form when flowing water removes all of original bones, leaving impression in sediment. Minerals fill in the mold Trace fossils- record activity of organism. Include nests, burrows, imprints of leaves, and footprints

TYPES OF FOSSILS Amber-preserved fossils- organisms trapped in tree resin that hardens into amber Preserved remains- form when entire organism becomes encased in material such as ice, volcanic ash, or immersed in bogs.

How are Fossils Formed? Fossils form when living things die and are buried by sediments. The sediments slowly harden into rock and preserve the shapes of the organisms Most fossils form in sedimentary rock Only 1% of life on earth becomes a fossil due to earth natural process (earthquakes, volcanoes etc)

The Fossil Record Provides evidence about the history of life on Earth. Shows that different groups of organisms have changed over time. Shows that fossils occur in a particular pattern. Older rocks have fossils of simpler organisms. Younger rocks have fossils of more complex organisms. In other words, the fossil record shows that life on Earth has evolved, or changed.