Prehistoric Planet 1x4 Ice Worlds Season 1 Season 0 5 EpisodesSeason 1 5 Episodes 1x1 - Coasts 1x2 - Deserts 1x3 - Freshwater 1x4 - Ice Worlds 1x5 - Forests Within the snow-covered forest, a tense standoff develops between ancient rivals, Pachyrhinosaurus and Nanuqsaurus.