Mark (Invasion of the Dinosaurs)

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

Behind the scenes

 * Coincidentally, John Crichton is also the name of the protagonist of the Australian science fiction series, Farscape. Crichton was played by Ben Browder, who later portrayed Isaac in TV: A Town Called Mercy.