The reptiles evolve, and the race for survival continues on land. Giant arthropods lurk in the Carboniferous forest, and sail-backed mammal-like reptiles fight for the survival of their young in the Permian.
Did You Know?
The amphibian that threatens the Dimetrodon nest, and eventually gets eaten by one of those creatures, is never named in the show. It is a Seymouria. See more
The second dust cloud that the antagonistic female Dimetrodon kicks up during digging appears a split second before she moves her leg. See more
Kenneth Branagh - Narrator
Even the air is alien. Over a third is oxygen, much higher than at any time in Earth's history. This oxygen-rich atmosphere has fueled the growth of new, super-sized arthropod predators.