Field Museum on Instagram: "Not actually a dinosaur. 🦕❌ Despite what the silver screen and the toy aisle tell you, Dimetrodon was NOT a dinosaur. In fact, it’s more closely related to YOU than SUE the T.rex. 🦖 Dimetrodon is a non-mammalian synapsid that lived 280 to 265 million years ago, about 25 million years before dinosaurs appeared. 🕰️ While Dimetrodon *does* share a common relative with dinosaurs, it’s a distant one that lived 315 - 330 million years ago. 🗓️"