1. Chapter 5

2.  SPI 0807.5.5 Compare fossils found in sedimentary rock to determine their relative age. I can:  Compare fossils found in sedimentary rock to determine their relative age.  Identify types of fossils.  Explain how fossils are used to interpret the past.  Explain the geologic time scale.

3. 1. Uniformitarianism: geologic change happen through slow gradual processes.  Most geologic change 2. Catastrophism: geologic change occurs suddenly by catastrophes.  Asteroid, comets, earthquakes, volcanoes I can explain how fossils are used to interpret the past.

4.  Examines the position within rock layers to estimate the age of an object.  Look for key words such as before, after, older, younger  Examples: Before the dinosaurs existed Older than my brother After the extinction of the dinosaurs  Bottom layers: oldest  Top layers: youngest I can compare fossils found in sedimentary rock to determine their relative age.

5.  Precisely measures the age of fossils or rocks in years.  Examples: 5780 years ago Born in 1900 At the beginning of the Triassic period I can compare fossils found in sedimentary rock to determine their relative age.

6.  Fossil (#36): Remains or physical evidence of an organism preserved by geologic processes. 1. Fossils in rock: formed when organism dies and quickly covered by sediment.  Hard parts of the organism are preserved  Soft parts decay I can identify types of fossils.

7. 2. Fossils in amber: entire organisms preserved inside hardened tree sap.  Insect gets caught in sticky sap, and then hardens.  Some of the best fossils. I can identify types of fossils.

8. 3. Petrification: minerals replace the organism’s tissues. I can identify types of fossils.

9. 4. Fossils in asphalt  Thick, sticky pools trap and preserve organisms.  The La Brea asphalt deposits in Los Angeles, California have preserved organisms for at least 38,000 years. I can identify types of fossils.

10. 5. Frozen Fossils  In 1999, scientists removed a 20,000-year- old woolly mammoth that was frozen in the Siberian tundra.  These mammoths became extinct about 10,000 years ago.  Because cold temperatures slow down decay, the mammoth was almost perfectly preserved. I can identify types of fossils.

11. Trace fossils: naturally preserved evidence of animal activity.  Tracks Reveal size and speed of an animal.  Burrows Preserved shelters.  Coprolite Preserved animal dung. I can identify types of fossils.

12.  Molds: a cavity in rock where an organism was buried  Sunk in/hole  Cast: created when sediment fills a mold and becomes rock.  Raised up I can identify types of fossils.

13.  Index fossils (#44): fossils of organisms that lived for a relatively short, well-defined geologic time span.  Ammonites  Marine mollusks similar to modern squid.  Lived b/t 230 million and 208 million years ago I can identify types of fossils.

14.  Trilobites  Closest living relative is the horseshoe crab  Lived about 400 million years ago  When scientists find fossils of trilobites anywhere on Earth, they assume the rock layers are also approximately 400 million years old I can identify types of fossils.

15.  Gives a rough sketch of the history of life on Earth.  Organisms with hard body parts have left more fossils.  Organisms that lived in areas that favored fossilization have left more fossils. I can explain how fossils are used to interpret the past.

16.  Show a history of environmental change.  Marine fossils found on mountaintops in Canada means that these mountains formed at the bottom of the ocean.  Detect the presence of ancient seas  Reconstruct ancient coastlines  Reconstruct past climates  Determine relationships and similarities between fossils I can explain how fossils are used to interpret the past.

17.  Earth is about 4.6 billion years old.  The Grand Canyon  Colorado River has cut/eroded away nearly 2 km deep in some places.  Represent almost half, nearly 2 billion years, of Earth’s history. I can explain the geologic time scale.

18.  Geologists divided Earth’s history into a scale with distinct sections of time. 1. Eons: largest division of geologic time Four eons: Hadean, Archean, Proterozoic, Phanerozoic 2. Eras: 2 nd largest division of geologic time 3. Periods: 3 rd largest division of geologic time 4. Epochs: 4 th largest division of geologic time I can explain the geologic time scale.

20. 1. Paleozoic Era (Old Life)  Marine life flourished, few land animals  Land plants appeared  By the end of the era, amphibians and reptiles lived on the land.  Ended with the largest mass extinction(#33) in history  90% of all species became extinct I can explain the geologic time scale.

21. 2. Mesozoic Era (Age of Reptiles)  Dinosaurs dominated the land  Small mammals  Birds  Ended with a mass extinction  15-20% of all species became extinct  Possibly caused by global climate change I can explain the geologic time scale.

22. 3. Cenozoic era (Age of Mammals)  Mammals flourished  Adaptations may have helped them survive the extinction of the dinosaurs caused by environmental changes. Regulate internal body temperature Develop young inside the mother I can explain the geologic time scale.