Several species of unidentified creatures have occurred in Primeval:
Several flocks of an unknown type of Pterosaur were seen flying above the Cretaceous beach and desert. (Episode 1.3, 2.2) One or two Pterosaurs were seen flying in the distance from a forest in the Cretaceous. Though they were most likely Pteranodon. (Episode 3.10/4.1)
- Several unidentified Pterosaurs appeared in a Episode 1.5 promo image despite not appearing in the actual episode.
A Badger like Mammal was a creature from the Early Cretaceous. The Anomaly Research Centre team encountered one Badger-like mammal in the Cretaceous coastal woodland eating a deceased Iguanodon calf. When startled, it snarled at the team and ran away into the undergrowth. (The Lost Island)
- It was possibly Repenomamus, a three foot long Early Cretaceous mammal that is known to have fed on small dinosaurs. It also may be either an undiscovered species of Mesozoic mammal or perhaps even a Didelphodon (which would be unlikely as it lived in the Late Cretaceous).
Four theropods of a unknown species were seen playing in the distance from the Cretaceous forest. (Episode 3.10). A year later, Abby Maitland had a sketch of another theropod, possibly the same species. (Episode 4.1)
- The CGI models used in Episode 3.10 appears to Giganotosaurus.
Small Future Birds
- As the bird's time period was presumably only a matter of centuries in the future, the birds may have similar biology as modern day birds.
Creature Sightings creatures
Several unidentified creatures were seen on several websites as Connor Temple searched for creature sightings. (Episode 4.2) The websites were:
- There was a herd of unidentified sauropods in the Cretaceous coastal woodland. (The Lost Island)
- Two unidentified theropods were captured by Tom Samuels. (Fire And Water).
- On some occasions, creatures were heard but not seen;
- Several creatures were heard on the Future Rainforest (Episode 3.5).
- Some creatures roared in the Cretaceous forest, though they may have been Raptors or the unidentified Theropods. (Episode 3.10)
- Captain Becker faced an unknown carnivore during Convergence. It squealed after Becker shot it with an EMD. (Episode 5.5)