The scene where Amy, Riddell, and Nefertiti stumble upon a sleeping Tyrannosaurus rex was almost cut as it was originally intended to feature 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.
Matt 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".
David Bradley (Solomon) would later play William Hartnell, who was the First Doctor, in An Adventure in Space and Time (2013). In subsequent series he would appear as the First Doctor himself.
Half of the triceratops was actually built and pushed by crewmen when Matt Smith, Arthur Darvill, and Mark Williams were riding it. The rest of it was filled in with CGI by The Mill.