The cladogram indicating the first appearance of three flight stroke features is below.
Class discussion or written assignment:
Look at the cladogram. There is direct fossil evidence that the shoulder and wrist of Velociraptor were capable of a wider range of motion than its earlier relatives. However, the fossil evidence does not indicate that the arms of Velociraptor were very long relative to leg length. So what might have been happening?
• If there were only a wide range of motion, was the animal capable of flight?
• If the animal was not flying, why did it have such a wide range of motion?
a. Propose a hypothesis about the evolution of the flight stroke.
b. Consider the questions above and use both direct evidence and inference.