Despite the fossil evidence that suggests that the raptor-like dinosaurs were covered (at least partially) with feathers, this show continues to show them with scales, a rather obsolete image nowadays. The animals in question are only shown to have worn feathers on the back of their heads, on their arms, and along their tails, or, in one case, nowhere. According to the creators, this is due to budget issues and technical limitations, although the episodes that focus on mammals did manage to animate the animals with hair.
Paleontologist Jim Kirkland expressed great dissatisfaction with the series, claiming that him and other scientists were filmed without knowing what the show was about or which part of their interviews would be used, and none of them had any say in the final product. The show's editing crew cherry-picked their lines to make it seem like they were supporting the series' fictitious claims and imaginary, unrealistic stories. Kirkland was appalled by the finished series.
The series famously featured a fight scenario between a Nanotyrannus and a juvenile Tyrannosaurus. Post-2010 research showed that Nanotyrannus was actually just a misidentified juvenile Tyrannosaurus, not a different animal species as previously thought, making this confrontation entirely baseless.
Originally, the series would have had an episode of Tyrannosaurus fighting Velociraptor, until the scientific advisers informed the producers that this idea is nonsense because the two animals did not live in the same time or on the same continent, and Velociraptor would have been dwarfed by Tyrannosaurus. The show's creators got around the issue by simply changing Velociraptor to Dromaeosaurus and having an entire pack clash with a Tyrannosaurus. The advisers still argued that a fight between these animals would never happen and they did not coexist either, but the episode was produced regardless as Raptor vs T-Rex (2008).