Dimetrodon

Dimetrodon was a mid-sized synapsid predator that lived in the Early Permian of North America, about 295 mya. Despite its superficial resemblance to dinosaurs, it was not one itself, being anatomically distinct and pre-dating them by over 50 million years. Dimetrodon’s most iconic feature is the large sail made up by its back vertebrae, which it used for display and to regulate temperature. Dimetrodon was about 12 feet long, 4 feet tall, and weighed 500 lbs.