Dimetrodon genus that flourished during the Permian Period, living between 280–265 million years ago (Artinskian to Capitanian stages). It was more closely related to mammals than to true reptiles such as lizards.
Dimetrodon was not a dinosaur, despite being popularly grouped with them. Rather, it is classified as a pelycosaur. Fossils of Dimetrodon have been found in North America and Europe, as well as a significant discovery of Dimetrodon footprints in southern New Mexico by Jerry MacDonald.