Dimetrodon, the most famous of all extinct synapsids! It's a shame most of that fame seems to include it getting called a dinosaur. It's both closer to us and much older than the dinosaurs! They lived about 290 million years ago during the early Permian in the southwestern United States, which was a swampy river delta area at the time. It was a carnivore about the size of a crocodile and, of course, had a rather impressive sail on its back that only a glimpse of made it into this portrait. I decided to restore it with the scaly skin that Varanopsids, an even earlier more rootward branch of the the synpasid family tree, are known to have, although bare skin with neither scales nor fur as Estemmosuchus had is also a possibility.