Day 36

1. Day 36 On your 4.5-meter geological timeline, about where would trilobites first appear? (You may use your books and notes to answer this.) Trilobites appeared toward the beginning of the Cambrian period, which was at the start of the Paleozoic era. They would be near the heavy line between the Paleozoic era and Precambrian time, on the today side of the line. Daily Warm-Up Exercises

2. Relative Scale and Magnification Exercise 7.1

3. CaSE Book Student Resources Book, page 51

4. CaSE Book Student Resource Book, pp. 52-53 and Lab Notebook, p. 51

5. Identify Index Fossils(Part 1, steps 2-9) Investigation 7 Fossils and Time

6. Fossils • Fossils are the remains or traces of organisms that have been preserved in Earth's crust. • They provide geologists with important evidence about prehistoric environments. • Some fossils also provide evidence of the age of rock layers. • These fossils are called index fossils.

7. Index Fossils • Not all fossils are Index Fossils. • Index fossils are fossils of organisms that lived for only a short time, but in many places around the world. Which would be a better index fossil: a fern that lived for 300 million years or a trilobite that lived in many areas for a few million years? The trilobite, because it lived for a short time over much of the Earth.

8. Index Fossil Key

9. Index Fossil Key • The Index Fossil Key shows the period in which the organism lived and whether it lived early, middle, or late in the period. • Early means toward the beginning of the period. Late means toward the end. • For example, early Permian rocks are older than late Permian rocks.

10. Index Fossil Identification Write the name of the Index fossil Write the age of the Index fossil Remember: Not all fossils are index fossils

11. Bryce & Zion Canyon Fossils • Identify the index fossils and their ages.