Art illustration - Dinosaurs - Nanotyrannus: ("tiny tyrant") is an extinct genus represented by a single species of theropod dinosaurs tyrannosaurid, who lived in the late Cretaceous period, about 68-66 million years ago, in the Maastrichtian, in what is now North America. It is the smallest known tyrannosaurid, since only measured about 5.5 meters long and 2 meters high, his weight of about 900 kg, short arms, legs and long legs.