Theropod dinosaurs are a diverse group of bipedal, carnivorous dinosaurs that were among the dominant predators of the Mesozoic era. Synonyms for the term "theropod dinosaur" include "meat-eating dinosaur," "carnosaur," "tyrannosaur," "velociraptor," "spinosaur," and "allosaur." These creatures ranged in size from small, agile predators like Velociraptor to massive, towering beasts like Tyrannosaurus rex. Some theropods even had feathers, such as the small, bird-like Microraptor. Despite their fearsome reputation, these extinct creatures played a crucial role in the ecosystem of their time, serving as top predators and contributing to the complexity and diversity of life on Earth.