Working titles for this story included
Bridgehead from Space and
Timescoop. The story title of the first episode was contracted to
Invasion in the opening title sequence, in an attempt to conceal the central plot device of dinosaurs. However, this was undermined by the BBC listings magazine
Radio Times, which carried a picture of a dinosaur in the listing for episode one. and felt the contraction for the first episode was silly, especially because the
Radio Times gave the game away. In a response letter after transmission, script editor
Terrance Dicks pointed out that all the titles used for the project had originated in the
Doctor Who production office. He agreed that the contraction to
Invasion was a decision he now regretted but noted that "
Radio Times are a law unto themselves". Location filming took place in September 1973, with studio recording commencing in October and November.
Missing episodes and archive All episodes of this story except Part One exist on original format
PAL colour master tapes, with the first episode only existing as a monochrome 16mm film print, but has since been
recolourised. A short clip from the end of Episode One, depicting the Doctor and Sarah Jane in the back of a Land Rover to be taken to the detention centre when the Land Rover encounters a tyrannosaurus rex, still survives in its original 625-line format, having been used as reprise at the beginning of Episode Two. There is a long-standing fan myth that the tape of Part One was erased by mistake, having been confused with an episode of the Patrick Troughton serial
The Invasion. In fact, BBC Enterprises issued specific instructions to wipe all six episodes of
Invasion of the Dinosaurs, named as such, in August 1974, just six months after the story's transmission; for reasons unknown, however, only Part One was actually wiped. Stickers on the cans for the remaining episodes 2–6 indicate that they were returned from BBC Wales, which was transmitting Season 11 in a different timeslot on Sunday. As far as the BBC was concerned, the story had been wiped in its entirety; researchers for the 1977 BBC documentary
Whose Doctor Who found that none of the episodes were listed as existing in the BBC Film Library, despite the fact that episodes 2–6 were actually at the possession of the BBC engineering department (they would be merged together into the BBC Film and Videotape Library in 1978). A black-and-white film print exists of the filmed sequences for Part One. This includes one scene of a scared scavenger stealing money from a dead milkman's satchel that was omitted from the broadcast version; this would have formed part of the deserted London montage. Black-and-white prints were used for practice by BBC film editors, in deciding where to make cuts, before cutting the master colour negatives. The surviving film recording of Episode 1 is the only tele-recording of a Season 11 episode held in the archives; this is probably due to the longstanding practice within BBC Enterprises of making a film print for overseas sales purposes prior to wiping any master tape. Colour 35mm film sequences from Part Five also exist, as does the initial edit of Part Three, without sound effects or incidental music on the soundtrack (known within the BBC as a "71 edit").
Cast notes John Bennett later returned to
Doctor Who as Li H'sen Chang in
The Talons of Weng-Chiang (1977). Peter Miles also appeared in
Doctor Who in other roles in
Doctor Who and the Silurians (1970) and
Genesis of the Daleks (1975), and in the radio serial
Paradise of Death. Martin Jarvis had earlier appeared as Hilio in
The Web Planet (1965) and later appeared as the Governor of Varos in
Vengeance on Varos (1985). ==Broadcast and reception==