Genus Edaphosaurus is a prehistoric reptile from the synapsid group that lived during the Permian period. Synonyms for this genus include Edaphosaurus bairdi, Edaphosaurus cruciger, and Edaphosaurus pogonias. These reptiles had a unique sail-like structure on their backs which they used for thermoregulation and displaying dominance. They were herbivores and could grow up to 3 meters long. Unfortunately, all species within this genus became extinct around 260 million years ago. Despite this, their fossils continue to provide insight into the evolution and diversity of life on our planet.