Paul MacCready with the head of a pterosaur model. He studies the head of?a flying, wing-flapping 1/2 scale model of the 11 m wing-span Quetzalcoatlus northropi (QN), largest animal to have flown on earth, extinct for 65 million years. ?The colors are conjectural, likewise the use of the head as a rudder. ?The project was undertaken in 1985 for the I-Max film 'On the Wing'. ?The head's side-to-side motion is used by the onboard auto-pilot to input rudder/yaw control.