UNIT corporal (Invasion of the Dinosaurs)

UNIT Corporal was the head of a roving team of UNIT soldiers left behind in an evacuated London to track time-displaced dinosaurs. (DW: Invasion of the Dinosaurs)

Behind the Scenes
UNIT Corporal was played by Pat Gorman, who played Soldier in Planet of the Spiders. It is not unreasonable to assume these two characters are one and the same.