- Creator Backlash: Dr. Thomas Holtz, a main consultant of the show, has said he disowns the mosasaur segment for its implausible depiction of mosasaur behavior.
- Development Hell: The DVD release has yet to materialize.
- Dueling Shows: With Planet Dinosaur.
- Flip Flop Of Dante: Some of species identifications for the show on the Discovery Channel website contradict what has been said by the director or consultants for the show. For example, the website calls the mosasaur and the sharks Mosasaurus and Squalicorax and the juvenile pachycephalosaur Pachycephalosaurus, but the director has said they are Tylosaurus, Cretoxyrhina, and a generic pachycephalosaur respectively.
- Science Marches On:
- The discovery that mosasaurs likely had tail flukes was published just as the mosasaur models were finished up.
- Yutyrannus shows that large tyrannosauroids were feathered as well as smaller ones.
- New remains of Beelzebufo suggest that it was not as large as originally assumed (and depicted in the program).
- Screwed by the Network:
- The second set of episodes were unfortunately set to air on September 11, 2011, the 10th anniversary of 9/11. As a result, the specials were removed at the last minute on the US version of Discovery Channel (Canada got the episodes as scheduled) so the network could air special repeats on Killing Bin Laden and US Navy Seals. Fortunately, the episodes were aired in the US two days later, albeit on The Science Channel. See also What Could Have Been.
- There's been some redemption on Discovery's part, however. It has agreed to not release a DVD until a product more worthy of the creative team's efforts can be released. A director's cut (the originally planned show without narration and talking heads) for Blu-Ray has since been confirmed and a feature film using the originally intended format of the show has been released.
- What Could Have Been: There were originally going to be six episodes of the show with the various stories arranged in chronological order, but two of them were cut and the final result had the stories arranged based on certain themes (eg: reproduction) rather than timeline. Among the known cut segments include one about hadrosaurs (intended to deconstruct the all-too prevalent but highly flawed cliché that their sole purpose in life was to be weak and helpless meat for tyrannosaurs, but was ultimately deemed too bland to concentrate on), one on the Early Cretaceous Yixian Formation with Raptorex, Psittacosaurus, and the baby-dinosaur-eating mammal Repenomamus, a story about the Triassic shellfish-eating reptile Henodus, a story about the Early Cretaceous La Amarga Formation, a story with Iguanodon and the strange theropod Concavenator, a story with a pair of the pachycephalosaur Prenocephale encountering a mother therizinosaur that got injured in a forest fire (a Shout-Out to A Nightmare on Elm Street and Freddy Krueger) and Alioramus, a story featuring a feuding Dorygnathus and Dimorphodon (as well as a plesiosaur), a story about a young Albertosaurus, a story about a herd of Styracosaurus, a story featuring spinosaurids, a story with Megapnosaurus, a story with Placodus, Nothosaurus, and Mixosaurus, a story about a coelurosaur that finds itself and wreaks havoc on a hypothetical island with superpredatory sphenodonts and flightless pterosaurs, and the Late Jurassic China story originally included the small ornithischian Agilisaurus, the pterosaur Darwinopterus and the crested theropod Monolophosaurus.
- The show was originally intended to do without narration and talking heads, but Executive Meddling changed that. It somewhat shows that in the final version, the narration tends to consist of cheesy phrases or stating the obvious.
- Furthermore, there were original plans to create a separate series called The Science of Reign of the Dinosaurs that would have had talking heads who would explain which parts were based on science and which parts mostly speculation.
- The role of Shunosaurus was originally written for a similar dinosaur, Spinophorosaurus, which did have a tail-club as large as that of the Shunosaurus in the program. However it had to be replaced, as creating models for contemporary predators would have been too expensive. Luckily, the animators already had existing models for Sinraptor, but unfortunately their original story got scrapped. The solution: Replace Spinophorosaurus with Shunosaurus, and put the Sinraptor model into its story, as these animals lived side by side. The enlarged tail-club of Shunosaurus ended up becoming an example of justified artistic license.
- The Eoraptor sequence from Evolution's Winners would have seen the reunion of Walking with Dinosaurs' Coelophysis, Postosuchus and Placerias. But the creators decided to shift settings, thus the Coelophysis "became" Eoraptor, Postosuchus was replaced by the very similar Saurosuchus and Placerias with Ischigualastia (hence why the animal received Placerias tusks).
- Word of God: Many exact identifications of the taxa shown are revealed by consultants or artists for the show instead of being named in the show itself.
- Working Title: Reign of the Dinosaurs.
Trivia / Dinosaur Revolution