The Forest of Dean - Permian hills Anomaly was an Anomaly linking the Forest of Dean in the present to a hill range in the Permian period. It was the very first Anomaly that the ARC/Home Office team discovered.
Circa 1998, a Gorgonopsid came through the Anomaly, and Helen Cutter fled through the Anomaly into the Permian from the Gorgonopsid. The Anomaly was open eight years later (suggesting it had either reopened or stayed open since 1998), and one Scutosaurus and a Coelurosauravus named Rex came through. The Coelurosauravus was found by Ben Trent then later adopted by Abby Maitland. While fleeing from a Gorgonopsid, Ben found the Anomaly and looked through into the Permian, before fleeing.
The following night, the Scutosaurus returned through the Anomaly, leading the Home Office team to it in the process. After obtaining legal permission from James Lester, Nick Cutter went through the Anomaly and into the Permian the following day with Rex and Captain Tom Ryan in search of Helen Cutter (and to return Rex). When the Anomaly began to weaken, Ryan and a reluctant Cutter returned through to the present, followed by Rex. The Anomaly then closed.
After a matter of weeks - months, the Forest of Dean - Permian hills Anomaly reopened (but this time linked to a point years earlier in the Permian than it had the previous time it was open). Helen Cutter subsequently fled through the reopened Anomaly from the Permian to the present, followed by a family of Future Predators. The Anomaly was almost immediately secured by the Home Office again.
After the Home Office team captured the Predator family's young, Nick, Helen, Captain Ryan and two of Ryan's other men went into the Permian through the Anomaly with the young, to locate and contain the Anomaly the Future Predators had come through to the Permian. The mother Predator also went through the Anomaly after them to rescue its young.
After Captain Ryan and both his men were killed in the Permian by the mother Future Predator, before the Predator herself was killed by a Gorgonopsid, Nick and Helen returned to the present through the Anomaly. When Stephen Hart refused to join her, Helen went back through into the Permian to find the future Anomaly.
Shortly after returning from the Permian, Cutter realised that the timeline had changed while he and Helen were in there. When the Anomaly began to close, Cutter tried to go through back through into the Permian to try and undo the change, but Stephen restrained Cutter, and the Anomaly closed before he could go through.
- It is uncertain whether or not, during the eight-year time between when Helen Cutter went through the Anomaly and when the Home Office found it, the Anomaly had closed and reopened, or had remained open during this eight-year period. If the latter is so, then this would make it the longest-lasting Anomaly known.
- In Episode 2.6 and 2.7, Oliver Leek had two Scutosaurus in his creature army. It is generally believed by fans that Leek obtained these Scutosaurus via the Forest of Dean Anomaly in the new timeline.