You can read the dimensionless speed from the graph in Fig. 3 if you know the relative stride length. The relative stride length simply means the distance between the animal s footprints divided by its leg length. The stride length of an animal is simply the distance from one part of the foot to the same part of the same foot the next time it lands. Using the drawing of the fossil footprints and the given scale, determine the stride of the Iguanodons in meters.
Leg length is the distance from the point where the upper leg bone joins the body to the ground.
Decide which leg to measure based on whether the dinosaur is bipedal or quadrupedal and your interpretation of the fossil tracks. When measuring, allow for a little bend at the knee of the leg, since most animals, including dinosaurs, hold their knees slightly bent. Calculate the relative stride length and use the graph in Fig. 3 to determine the dimensionless speed of this dinosaur. With most animals, a dimensionless speed of 0.7 is the dividing point between walking and running.