A large (several metres long) Labyrinthodont with a very long tail, and a juvenile, appeared in a seaside cave in episode 4.5. The adult had been causing many people and animal stock to go missing over the ten years since the anomaly had previously been open. It killed someone camping out to investigate the 'Witchfield Worm', and Matt Anderson saved a fisherman from been devoured too. Abby Maitland pursued the creature to a campsite where she lured it on top of a caravan and drove it part way to the anomaly site. Connor Temle discovered the infant in the cave, and its cries of pain caused by acid drew the adult back. It killed two people, one of whom had known about the creature and attempted to contain it, before being driven back through the anomaly by Connor and Abby.
- Most species of Labyrinthodont actually had smooth skin, not thick scales (although Temnospondyls which are a group of Labyrinthodonts had scales so this creature may be a Temnospondyl).
- The Labyrinthodont in Primeval looks like a cross between a crocodile and a worm (along with an eel looking body), but in real life, it looks more like a salamander.
- The young Labyrinthodont was actually the right size as a real life labyrinthodnt, but its mother labyrinthodont was very large than a real life labyrinthodont.
- This is Tim Haines' favorite creature in Series 4 and 5.
- According to the Primeval official site, this Labyrinthodont encountered at Witchfield Cove is native to Poland.
- The Labyrinthinodont appears in the Primeval: New World teaser trailer.