Theropods are a group of bipedal dinosaurs known for their carnivorous diet. They belong to the clade Dinosauria and are characterized by their hollow bones and three-toed limbs. Famous examples of theropods include the Tyrannosaurus rex and Velociraptor. These dinosaurs lived during the Mesozoic Era and were the ancestors of modern birds. Theropods varied in size and shape, ranging from small, agile hunters to large, powerful predators. Their adaptations, such as sharp teeth and claws, made them effective hunters in their ecosystems.