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• Evolutionary Essentials
When the Permian Period began 290 million years ago, the continents were drifting together to form one enormous landmass called Pangaea. A patchwork of different environments, Pangaea contained climate zones that included everything from dry deserts to tropical forests.
New tetrapods—four-legged vertebrates—roamed these diverse habitats. A key development in their reproductive process affected the evolution of life in the coming eras:
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The development of the amniote egg let tetrapods reproduce and live full-time on dry land.
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With this development, animals no longer need to remain near the water’s edge to lay their eggs. They could now survive further inland in drier parts of Pangaea.
Continue to The Amniote Egg. >>
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