From Ohio History Central
Reptile remains in Ohio's Upper Paleozoic rocks are very rare and generally poorly preserved. The Linton locality (see Amphibians), despite more than a century and a half of collecting, has produced only three species of reptiles represented by a total of 10 specimens. A few fragmentary remains have been reported from Upper Pennsylvanian rocks in eastern Ohio.
Permian rocks have been a bit more productive for reptile remains but they are scattered and fragmentary. Perhaps the most characteristic reptile remains from these rocks are isolated skeletal elements of the sail-backed, mammal-like reptiles, Dimetrodon and Edaphosaurus. Both were comparatively large reptiles with large, fan-shaped sails on their backs. These structures are thought to have been used to control body temperature. Dimetrodon was carnivorous whereas Edaphosaurus was herbivorous. Remains of turtles and snakes have been found at a few Pleistocene sites in Ohio.