* ExecutiveMeddling: For the ''Walking with Dinosaurs'' movie - 20th Century Fox decided to add voices to the dinosaurs to help kids get the film, but the decision was made really late in production to the point where there isn't even lip syncing. The majority of viewers disliked the change, as they found the voices annoying and distracting.
* HeyItsThatVoice: The narrator is, of all people, [[Film/HarryPotter Gilderoy Lockhart]]
** [[WesternAnimation/IceAge Sid the sloth]] is the narrator for the 2013 film.
* WhatCouldHaveBeen:
** ''[[StockDinosaursTrueDinosaurs Baryonyx]]'' and ''Cetiosaurus'' were to appear in the main series, but they were replaced with ''[[StockDinosaursTrueDinosaurs Utahraptor]]'' and scrapped entirely, respectively.
** The ''Sea Monsters'' book describes a number of scenes that didn't make it into the series, such as the female [[UsefulNotes/PrehistoricLifeNonDinosaurianReptiles nothosaurs]] leaving their eggs on the beach at night (there is also a picture of Nigel inspecting those eggs, meaning it was filmed) and Nigel meeting the utterly bizarre [[http://en.wikipedia.org/wiki/Thalassocnus aquatic ground sloth]] ''[[UsefulNotes/PrehistoricLifeMammals Thalassocnus]]'' before going to look for the shark ''[[UsefulNotes/PrehistoricLifeOtherExtinctCreatures C. megalodon]]''.
** Originally ''Walking With Beasts'' was going to air first (the idea being that the trilogy would be moving backwards through time), but they only recieved enough money for a show about dinosaurs, and they made ''Walking With Dinosaurs''.