WHERE CAN I SEE THE SEA?

CRAIG A. MUNSART and KAREN ALONZI-VAN GUNDY

INTRODUCTION

Understanding how the pieces of the fossil puzzle fit together allows the paleontologist to imagine the earth as it was millions of years ago. Introduce the activity to the students by telling them that they are all paleontologists and have found many different fossils. Based upon those fossils, they will have to draw a map showing what environments were present in a certain area more than 70 million years ago. (Note: This activity will use drawings of fossils. When available, actual fossils should be used to replace the drawings. In an ideal case, only actual fossils would be used. See the list of fossil sources at the end of the lesson.)

Time: 45-90 minutes

MATERIALS

— Copy of prepared grid (Figure 1) for each student
— Fossil figures and descriptions (Figures 2, 3, and 4), enlarged if possible, cut apart, and placed on individual 3" x 5" cards, one for each student. (Duplicates can be made as needed to accommodate a larger class.)
— Watch or clock that indicates seconds
— Blue, yellow and green colored pencils for each student.
— Pencil with eraser for each student.

DIRECTIONS

Part 1: Filling in the Grid: At the outset, students will sit at their regular seats. At predetermined intervals (1 1/2 to 2 minutes) students will move to the next seat according to a planned sequence determined by the teacher. This seat switching will be repeated until each student has had the opportunity to sit in every seat.

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1) Have all students stand to one side or the back of the room. Each student should have a pencil and eraser.
2) Place one of the fossil figures face down at each seating position.
3) Explain to students what will be happening: "In front of each seat is a card showing a fossil, a description, and a number. It is now face down. Do not turn them over until I ask you to do so. When I ask you to return to your seats, go to your regular seats but do not touch the card in front of you."
4) Have students return to their seats.
5) When students are seated, give one of the blank grid sheets (Figure 1) to each student and have them fill in their names and the date.
6) Explain a grid. Show Figure 1 on the overhead projector.
7) Ask students to turn over the card in front of them and give them the following directions: "Each space on the grid has a number and each card has a number. Find the space on your grid that has the number to match the card. In that space draw the picture of the fossil found on the card and write the name of the fossil underneath it. You will be moving from one seat to another until all the grid spaces are filled. You will only have two minutes to fill in the grid and move on to the next seat, so it is important to pay attention, draw quickly, and concentrate on what you are doing."
8) Draw the plan of seating changes on the board and tape arrows to the desks or tables so students know which seat to move to next.
9) Use the first move as a practice. Tell the students what signal you will use to indicate it is time to move (e.g., say "Go," blow a whistle, or ring a bell). Make certain they understand what is expected of them before continuing.
10) Have students proceed until all the grid spaces are filled in with a drawing of the fossil and its name (see Figure 5 which shows the completed grid).

Part 2: Interpreting the Grid Once the grid is completed, the students should use dots and hatch marks to separate the different types of environments (Figure 6). Show examples of how to do this on the board. Discuss which fossils might indicate which environments. The normal sequence would have any fossils indicating a beach found in between those of the ocean and the land. For this part of the activity, students may work as individuals or pairs. Working in groups of more than two becomes difficult. Students should color their filled in grids as follows: boxes with land fossils, green; beach fossils, yellow; and sea fossil, blue.

Allow students to discuss their own interpretations and their reasons for separating environments. Make an overhead transparency of the solution (Figure 6) and show it to the class, placing it on top of the transparency of Figure 5, after you have graded the papers. Discuss with students any different interpretations they may have.

EXTENSIONS

If actual fossils are used, some time should be taken to explain their ages and types.

Assign different environments to students (individually or in small groups) as subjects to research in the library. Their task is to identify as many "fossils" as possible that might be found 50 million years from now. They should also describe other things that might indicate that particular environment (e.g., sand dunes on a desert).

Research different animals to see how they are adapted to their environments (e.g., flippers for animals at sea, webbed feet for aquatic birds).
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RESOURCES

The United States Geological Survey in Denver, Colorado, has hands-on fossil kits available for loan (for Colorado teachers only). The hundreds of fossils contained in the kit represent a broad spectrum of organisms, from plants to dinosaurs. For information contact the U.S. Geological Survey Library GEO Center at (303) 236-1015 (Denver, Colorado). The Colorado School of Mines also has fossil kits for loan. Information can be obtained by calling the Geology Museum of the Colorado School of Mines at (303) 273-3823 (Golden, Colorado).

Other fossil sources might be state government geological surveys, local universities, high school earth science or geology departments, or clubs of amateur collectors. Often, such clubs congregate at fossil or mineral shows where specimens are on display and for sale. State geological survey departments are also excellent sources of free or inexpensive publications about where to find fossils in your area. Local rock shops (frequently with a large fossil inventory) are often owned by education-minded entrepreneurs who can be quite generous, either with small gifts or loans.