Mark (Invasion of the Dinosaurs)

Mark, formerly known as John Crichton, was a British athlete who jumped 2.6362 meters in one of the Olympic Games. He was one of the people selected by Sir Charles Grover to colonize New Earth. Sarah Jane Smith convinced them that they were not aboard a spacecraft at all. (DW: Invasion of the Dinosaurs)

Behind the scenes

 * Coincidentally, the name John Crichton is also that of the hero of the early-2000s Australian science fiction series, Farscape.