The dimetrodon belongs to the genus of carnivorous dinosaurs. It is so named because it had a large skull with two different types of teeth. It grew up to 3.5 metres long and lived about 299 to 272.5 million years ago in the early Permian period. In addition to the long tail, the dimetrodon had large claws on the feet and walked on four side-sprawling legs. Its weight is estimated at about 250 kilograms. The most distinctive characteristic of dimetrodon was the spectacular sail on its back which has traditionally been explained as an adaptation to regulate body temperature. Fossils of dimetrodon have been found in the U.S. States of Texas and Oklahoma as well as in Europe. Very well-preserved examples come from Thuringia in Germany.