Labyrinthodont

Labyrinthodonts were large amphibious creatures which lived in the Palaeozoic and the early Mesozoic era.

Real life
Labyrinthodont (name meaning "maze-toothed") was a subclass of amphibian which existed from 395 to 120 million years ago. It is ancestral to all terrestrial vertebrates

Trivia

 * This was the first amphibious creature to appear in Primeval.

Errors

 * It was stated that Labyrinthodont had highly reduced limbs, but in Episode 4.5, it had powerful legs and could even stand upright for several seconds.
 * The Labyrinthodont should have had smooth skin, not thick scales, covering its body.
 * The Labyrinthodont had upper and lower teeth in the series, but in real life they were smaller.
 * The labyrinthodont in the show looked like a worm salamander with crocodilian-like scales, but in real life, it was more like a regular salamander.
 * The Labyrinthodont was shown to be able to live very well out of the water, but in real life it would have needed to wet its skin from time to time.
 * The Labyrinthodont in Primeval was shown to have the ability to climb up things like trailers, but in the reality Labyrinthodont was strictly firmed to the ground.