- Completely Different Title: The French title is "La Révolte des intra-terrestres, première partie" (Revolt of the Intraterrestrials, Part 1).
- Deleted Scene: The completed episode had a running time of sixty minutes, requiring over fifteen minutes of footage to be removed to fit its broadcast slot. Much was originally made of the fact that the Discovery Drilling Project was under pressure from its financial backers to reach greater depths more quickly.
- A deleted scene depicted Amy discussing with the Doctor how she had seen herself with Rory ten years in the future, and if that would really happen.
- Promoted Fangirl: Meera Syal, who was cast as Nasreen, had been a fan of the series since childhood and had been trying to secure a role in the show since its revival in 2005 and was pleased when she received it.
- What Could Have Been:
- Chris Chibnall wanted to take the redesign of the Silurians a step further and reveal that they always had human-like faces, and just wore masks over them in their classic series appearances. Showrunner Steven Moffat overruled him, however, and instead established that the Silurians here were a different subspecies to the ones seen previously.
- Originally, Mo and Amy were to be stripped down to their underwear before being dissected. This was removed as "too adult".
- One major story element that was ultimately excised from the script was a new monster called the Armasaurs, armadillo-like dinosaurs which would emerge from the Silurians' shafts to abduct people. Due to budget constraints, it was replaced with the bioprogrammed quicksand.
- Chris Chibnall also considered bringing back the Sea Devils, but decided that doing two races of monster was much tougher and the story was "so clearly about the Silurians and what the Silurians want".
- Working Title: The Ground Beneath Their Feet.
Trivia / Doctor Who S31 E8 "The Hungry Earth"