The Geological Society of America.
Adapted from Hands on the Land, Garden Park, Canon City, Colorado. Adapted with permission.
Paleontologists are the geoscientists who discover and study fossil evidence of past life. Sometimes they even find the footprints of dinosaurs that roamed the surface of the Earth long ago. Ever wonder how paleontologists are able to determine, based on fossil evidence, whether a particular dinosaur was walking or running when it left footprints behind? These two activities will help you to learn how these scientists can do that.
- Metric measuring tape
- Graph paper and pens
- Measure the foot length, hip height, and overall height of each student in class who is willing to be measured. Hip height is measured from the ground to where the top of the femur (thighbone) joins the pelvis. To find this spot, lift a leg so the femur is parallel to the ground, then see where the top of the femur joins the pelvis.
- Create a table to record the data. Plot foot length against hip height and total height.
- Discuss: Is there a strong correlation between the two? If not, why might that be? If you measured the foot lengths and hip heights of animals, do you think the correlation would be stronger or weaker? Why?
- In a group of four students, measure out a course of 20 meters and use tape to mark the beginning and end. Designate one student the strider, one the timer, one the measurer, and one the recorder. Each has a job to do:
- It is the strider’s job to walk the course, and then run it.
- The timer sets the strider in motion by saying “Go!” The timer uses a stopwatch to determine how long it takes for the strider to travel the length of the course.
- To determine the strider’s stride length when walking and running, the measurer counts the strides taken and divides the length of the course (20 m) by the number of strides.
- The recorder determines the strider’s speed by dividing the length of the course by the time in seconds (meters per second). The recorder enters stride length and speed into the table.
- Switch roles with other group members and repeat this process until all students rotate through all positions.
- Plot the relationship between stride length and speed on a scatter graph.
- Discuss: Based on your group’s data, is there a strong correlation between stride length and speed? If not, why might that be? If you combine your data with those of other groups, would that strengthen or weaken the correlation? After this experiment, do you think this method is an accurate way of studying dinosaur tracks? Do you feel confident that you could apply this method to dinosaur tracks?