 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 . 
