- Accidentally Correct Writing: Obscure pterosaur Ornithodesmus (now known as Istiodactylus) is depicted as a scavenger, while at the time, it was thought of as a fish eater. In 2012, Mark Witton did some research and confirmed that Istiodactylus was indeed a scavenger.
- Accidentally Correct Zoology: Bakker included a therizinosaur ("segnosaur") in the story even though none were known from the right time and place when the book was written. (Perhaps not coincidentally, it was depicted as a mountain dweller, therefore living in an environment unlikely to preserve its fossils.) A decade later, a therizinosaur (Falcarius) contemporaneous with Utahraptor was published.
- Science Marches On:
- The book came out just before dromaeosaurids like Raptor Red and her kin were confirmed to have feathers. To be fair, it's just about the only birdlike trait the Utahraptors in this book don't have. That still doesn't stop other artists from drawing Red and the other dromaeosaurids with feathers, though.
- The taxon Ornithodesmus shows up in the book as a pterosaur. Turns out that it was actually a misidentified dromaeosaurid, the first named. The pterosaur material with the fossil has been named Istiodactylus. Bakker was right about Istiodactylus being scavengers though.
- Therizinosaurs are depicted as featherless burrowers, and are referred to as "segnosaurs." They're now considered to have been feathered, although digging may be plausible. In addition, several of the illustrations depict them as quadrupeds (or at least crouching), but it is now known that therizinosaurs were bipedal, like other theropodsnote .
- Iguanodon didn't live in North America. The partial skull formerly classified as this genus has been reassigned to Dakotadon.
Trivia / Raptor Red