Humorously enough, his Ice Age costar, Ray Romano was picked to host the Discovery Channel premier of "Walking With Beasts" in order to promote Ice Age.
Executive Meddling: 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. The DVD thus contains a "Cretaceous cut", which cuts out all the voices.
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 slothThalassocnus before going to look for the shark 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.
Among the proposed episode ideas for WWB was one based around the Riversleigh fossil site from Australia. They chose to abandon it, as they already had enough stories planned.
For people wondering, such episode could have featured diprotodonts, thylacines, a Gastornis-like bird (Bullockornis), running crocodiles and a python (since then included into Morelia, but hard to believe they would pass the chance to drop the original name Montypythonoides).