 The production team had to be mindful of the series'budget when planning the effects and sets; Chibnall commented that "it would be very easy to spend £ 300m on this but we don ’ t have it". As such, the dinosaurs could not dominate the episode, and Chibnall had to tell "a big other story". The scene where Amy, Riddell, and Nefertiti stumble upon a sleeping Tyrannosaurus rex was almost cut as it was originally intended to feature computer-generated (CGI) raptors, which were too expensive. However, Millennium FX realised they could use a baby T-Rex that had been in an exhibit they designed. The episode contains a variety of "favourite" dinosaurs; some were built from scratch, while others were CGI. Smith had to wear padded trousers when riding the triceratops, and recalled it was "a painful couple of hours, a laugh though and definitely worth it". Half of the triceratops was actually built and pushed by crewmen when Smith, Darvill, and Williams were riding it. The rest of it was filled in with CGI by The Mill. The Doctor Who logo in the title sequence featured the texture of a dinosaur's hide, in keeping with the varied "blockbuster" themes for each of the opening five episodes of the series. A preview clip of the episode was released at the 2012 San Diego Comic-Con International.
