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Edaphosaurus
A sail-backed edaphosaurus forages amid a Permian landscape in this artist's depiction. These primitive predators, along with their close relatives the dimetrodons, though dinosaur-like in appearance, are actually considered the forerunners of mammals. Scientists think their large back fins were used to regulate body temperature.
Artwork by Interfoto Pressebildagentur/Alamy

Permian Period

See photos and illustrations of the plants and animals of the Permian period from National Geographic.