In the DVD commentary, Wanda Ventham states that her appearance in this story marked her first major acting job since giving birth to her son, Benedict Cumberbatch.
Louise Jameson claims the reason her hair is done up in this episode is because a BBC hairstylist had mistakenly cut six inches off her hair just prior to filming. Her final scene in the story was filmed some five weeks after this incident, by which time her hair had grown long enough to allow her to wear it down for a single scene.
The script was written before it was known that K9 would be a regular character. Rather than incorporate him into the story, Chris Boucher added a scene where K9 malfunctions.
Adam Colby's dog is named "Leaky", obviously named after a very famous palaeoanthropologist family headed up by Louis and Mary Leaky, which after all is his field.
This story introduced a new version of Leela's famous leather outfit. It was noticeably lighter in colour than the last. The new version was created because the original was wearing out. Furthermore, it had caused Louise Jameson some problems because it was a leotard. The new version, by contrast, was actually a dress. Graham Williams had also instructed the designer, Amy Roberts, to make Louise look sexier in the new outfit. The original leotard appears briefly at the end of part four (mainly to facilitate the punchline to a joke in part one) and would return in the following story, "The Sun Makers", before the new version came back for Leela's final stories.