Dimetrodon was a mammal type reptile which belonged to a family called Pelycosaurs, which had both mammal and reptile characteristics. Dimetrodon came before the earliest dinosaurs by more than 40 million years but is often confused as being one. It is often referred to as mammal-like reptile, due to characteristics of the skull and tooth pattern. Dimetrodon was the largest carnivore (meateater) of the Permian period (some grew almost 10ft.). It was a predator
This pelycosaur had a large sail on its back, supported by long, bony spines, each of which grew out of its backbone. The sail may have controlled body temperature by absorbing the heat from the sun's solar rays and warming the blood and body of Dimetrodon. It warmed up after sunrise and cooled off slowly during the heat of the day. The sail may have also been used for attracting a mate or for making it look muchlarger than it was to other predators. Dimetrodon had a large skull with two types of teeth (sharp canines and shearing teeth). It was probably slow because it walked on four side-sprawling legs but would probably wait to ambush its prey, in this case, a 6 ft. long amphibian named Eryops
.- Professor Saputello