about 3 years
Sometimes in a toy dinosaur set you’ll find Dimetrodon, the one with the massive sail on its back. But Dimetrodon doesn’t belong with the dinosaurs. In fact, it’s not even a reptile. Although misidentified, Dimetrodon ranks as one of the most recognizable of extinct animals because the form of its sail is quite memorable. But it’s the sail’s function that is the real mystery.