With Primeval: New World coming on and the original series probably having taken its last breath, why not suggest a new spin-off that takes off more directly from the British series? A sort of "lost years" series, if you will. A sort of "Abby and Connor stuck in the Cretaceous for a year" series. What fan wouldn't want to see that?
Just imagine what a show like this would be. It would have to be a short series, maybe one or two seasons (depending on season length). Connor and Abby could be the only human characters, but who's to say they couldn't meet some other groups while they were there? Groups like the one Emily traveled with. They wouldn't join the group because they wanted to stay at their anomaly site. And if that seems to be wandering too far, no worries: I would have absolutely no problem watching a whole show with no one but Hannah Spearritt and Andrew Lee Potts.
Just think of how filming this show would be. No other actors, per se, but plenty of creatures. So they would either be constantly interacting with thin air or with stand-ins (like "Dave the Lodge"--watch this interview to hear about him). (Unless Andy Serkis came along to play a dinosaur Connor and Abby became particularly attached to--but that would be a whole new topic, wouldn't it?) There would have to be quite a CG budget and something of a location budget, too, but not too many sets (as in buildings, rooms, that sort of thing).
We could see them sculpting tools, building their shelter, recording the plant and animal life, sightseeing the surroundings in fear and excitement. Deciding what was good to eat and what wasn't, helping each other along with different tasks. The difficult thing would be that their spirits would slowly sink lower and lower as the series went on and their situation became more hopeless, and the finale wouldn't really even be able to show happiness restored because that's Primeval Episode 4.1.
Which brings me to naming this show. It wouldn't be bad as Primeval: Lost World, but of course somebody has already taken that, haven't they? Primeval: Forgotten World might work, though it's a little longer. But I like it more than Primeval: Abandoned--and Primeval: Stranded would be an ode to the movie Stranded Andrew was in some years back. Or what about Primeval: Lost Discovery?