Rock Cycle - Past Life (1B)

  • Modeling dinosaur tracks
  • Comparing footprint patterns.
  • dinosaur
  • footprints
  • tracks
  • bipedal
  • quadrupedal
  • workbook or paper
  • talcum powder or cornstarch
  • shallow pans
  • rope
  • butcher paper (optional)
  • paper footprints

Students create tracks using talcum powder and interpret results.


Like body fossils, trace fossils of extinct animals, such as footprints, can only be interpreted through comparison with living animals. Paleontologists thus try to understand dinosaur track ways by studying the tracks of different types of large mammals in a variety of modern environments. Mammals are the best modern analogs for dinosaurs because they walked erectly, like the dinosaurs. For example, elephant tracks and Apatosaurus dinosaur tracks are very similar. In contrast, modern reptiles have a sprawled stance that produces a different type of track way than either dinosaurs or mammals.

Since we are bipedal mammals, we can make tracks that mimic the tracks of quadrupedal (with four legs) and bipedal (two legs) dinosaurs. In this lab students will pretend to be different types of dinosaurs which move at different speeds. They will produce track ways with several distinctive patterns.

  1. Students have learned that footprints can give paleontologists information about how an animal lived or walked. In this activity, students will "play act" that they are four legged animals walking in the mud or sand, leaving behind footprints. This activity is a lot of fun, but it may get the students overexcited. If you have parent helpers, this would be a good day to have them in the classroom. We also highly recommend that you conduct this activity outside.
  2. Divide the class into two or three groups. Have the students pretend that they are dinosaurs. Have them walk, run, and jump like they think dinosaurs did before they use the talcum powder or cornstarch
  3. Have the students make footprints on butcher paper (if you remain inside) or outside on the school playground. Put the talcum powder or cornstarch into shallow pans. Demonstrate how to make footprints by having one student step into the powder, and then walk on the paper or playground. Observe the pattern of footprints. Have a teacher or adult do the same thing. See if there is a difference in the size of the print and the length of stride. Would similar differences in dinosaur tracks indicate a difference in the size of the dinosaurs that left the tracks?
  4. Now demonstrate these other ways of making footprints:
    1. Have another student step into the powder and then walk and drag the rope (which has also been dipped in powder). Now observe the track left by dinosaur that dragged its tail.
    2. Have a child dip both hands and feet in the powder and walk four-legged. Try this two ways: 1) moving the right hand, then the left leg, then the left hand, and then the left leg, and 2) moving both right limbs together, then both left limbs together.
  5. After you demonstrate, you may want the students to go to separate areas of the playground and have them make their own footprints. Also, you may want them to draw the types of footprints which you demonstrated
  6. Return to the classroom. Using the worksheets, lead a discussion of the results of your track way experiments. Students should be able to answer such questions as:
    1. Are footprints farther apart when an animal is walking or when it is running? (Answer: running);
    2. How can you distinguish a two-legged animal's prints from a four-legged animal's prints? (Answer: placement and spacing of prints; presence of foot + hand prints);
    3. How can you estimate the length of an animal's legs from its tracks? (Answer: distance between footprints is longer for people/dinosaurs with longer legs than for those with shorter legs, for two animals moving at the same speed);
    4. How do bipedal dinosaur tracks differ from human tracks? (Answer: distance between prints should be shorter).
  7. Have students cut out the footprints and hand prints on the following page. Instruct them to paste them onto the worksheet in three different track ways. Monitor their patterns to ensure that they create realistic track ways. Have them add a tail in one of the patterns using a pencil or crayon.

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