• What Could Have Been:
    • Baryonyx and Cetiosaurus were to appear in the main series, but they were replaced with 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 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 aquatic ground sloth Thalassocnus before going to look for the shark C. megalodon.
    • Originally "Walking With Beasts" was first, but they only recieved money for "A show about dinosaurs", and they made Walking With Dinosaurs.