Review with your class what a paleontologist is, how they find evidence of dinosaurs and what form this evidence takes. Talk about the need to accurately and completely describe any finds they make. Review possible describing words, how to measure with a ruler, etc.
To make the fossil rocks for this experiment, you will need one 12 ounce juice box and one approximately 2 inch long plastic dinosaur model for each student. You will also need 1/2 cup of plaster of Paris and 1/2 cup of sand per student.
Cut the front off the juice box and rinse it. Put 1/2 cup of plaster and 1/2 cup of sand in a mixing container. Add 1/2 cup of water. Let it sit until all of the water is absorbed, then stir until well mixed. Pour a layer (approximately 1/4 inch thick) of plaster into the juice box. Put the dinosaur on top and cover with the remaining plaster. The entire dinosaur should be covered.
Set the box aside and let it dry over night. Rinse the mixing container right away if you want to clean and reuse it. Make one of these boxes per student. The next day, tear off the juice box leaving a "fossil rock" ready for a paleontologist to examine.
Have a broom and extra trash can on hand.
The purpose of this activity is for the students to see that it is harder to figure out what a dinosaur may have looked like when the bones from several animals are mixed together.
Make sure your class knows how to use a stopwatch or read minutes and seconds off a clock. Review how to add minutes and seconds or just use seconds.
The students should do this activity in teams of two. Make one copy of the following sheets for each team of students.
Discuss ways paleontologists figure out which bones go together and how. Sometimes they make mistakes such as mixing up the neck and tail or attaching the wrong head. Talk about how a dinosaur might use its tail. Have the kids think about how a cat uses its tail for balance.
Kids can simulate this with themselves as follows: have a child stand up and bend at the waist with her hands on her knees. Then, have her extend her arms in front to simulate a long neck. She must compensate for this additional weight by putting more weight behind her. Since she doesn't have a tail, the class will see her stick her rear end out as her "neck" extends.
A dinosaur with spikes on its tail probably protects itself by fighting. It's reasonable to assume, therefore, that the body of the dinosaur has additional armor or weapons.
Talk about camouflage and what it's purpose. Give examples from living animals. Talk about habitats and what sort of clues paleontologists might find that help them figure out what type of habitat was in an area.
Have a discussion of the answers to items 1 and 2 in the lab worksheet. Let the kids exchange ideas and observations. An enlargement of the footprints would be helpful.
To study human locomotion, you will need paper about 15 feet long. This leaves enough room for the kids to run along the paper. If the paper is less than 30 inches wide, use four strips, one for each set of footprints. Otherwise, you can put set A and B on one sheet and C and D on another. You will also need a hallway, sidewalk, or other flat area at least 20 feet long.
A number of children can actively participate in this experiment: 4 as dinosaurs, 2 to manage the paint, and 2 to hold each strip of paper down.
To make the tracks:
1. Set up the paper.
2. Prepare the dinosaurs:
Two kids should put plastic bags over their bare feet and tape the bags so they are snug.
One child should put on plastic gloves.
The fourth child should both cover their feet and put on gloves.
3. Prepare the paint. Pour a small amount of tempra paint in a flat pan big enough for a child's foot. Use the paintbrush to spread this paint into a thin layer. Add more paint and spread it as necessary.
Note: Remind the dinosaurs to stay on the paper to keep paint off the floor. Don't worry about messing up the tracks at the ends of the strips.
4. Make tracks A and B. Have the dinosaur (feet covered only) step into the pan and get paint on his feet. Then he should walk normally the length of the paper. Have the paint people label this Track A. The dinosaur needs to walk down the edge of the paper to get back to the starting point. After getting more paint on his feet, he should run down the paper to the side of his first tracks. Have the paint people label this Track B. This dinosaur can clean up.
5. Make track C. Have the dinosaur with both hands and feet covered get all four covered with paint. She should then walk down the paper on all fours. Have the paint people label this Track C. This dinosaur can clean up.
6. Make track D. Have the dinosaur with only hands covered get painted. She should then walk down the paper on her hands. This can be done by walking on all fours but, since only the hands are painted, it will appear as if she walked on her hands. This track should be to the side of track C.
Have the last dinosaur get his feet painted. He should follow the same path, walking normally, so that the two sets of tracks are on top of each other. Have the paint people label this double set of prints Track D. These dinosaurs can clean up.
7. Clean up and bring the tracks into the classroom for study.
Tracks C and D obviously have two different types of footprints. In track C, the footprints have the same strides which one would expect of a four legged animal. Also, they follow the same path. In track D, the two types of footprints have different strides and follow slightly different paths, so one might reasonably expect them to be made by two 2-legged dinosaurs of different species.
Discuss dinosaur names and their meanings. Review how animals are classified and why.
