Input (grade 13): Swampy habitats like shallow wetlands, coastal lagoons and large brackish river deltas also existed at this time, and there is much to suggest that this is the kind of environment in which the tetrapods evolved.
Output (grade 7): Swampy habitats like shallow wetlands, coastal lagoons and river deltas also existed at this time. There is much to suggest that this is the kind of environment in which the tetrapods evolved.