Final answer:
Ceratosaurs are theropods known for their unique pelvis structure and often distinctive ornaments like horns or crests. They were part of the carnivorous dinosaurs from the Late Triassic to the Late Cretaceous period. This clade is critical for understanding dinosaur diversity and the evolution of birds.
Step-by-step explanation:
Ceratosaurs are a clade of theropod dinosaurs that can be distinguished from other theropods by several anatomical features. One of the main distinguishing characteristics of ceratosaurs is their unique pelvis structure, which differs from the typical 'lizard-hipped' pelvis of other saurischian dinosaurs. Also, they often possess a distinctive ornamentation, such as horns or crests, notably seen in genera like Ceratosaurus.
The clade includes a variety of carnivorous dinosaurs that lived during the Late Triassic to the Late Cretaceous period. Ceratosaurs showcase a wide diversity in size and form but share common ancestry, which is expressed in their anatomical commonalities. These features can be analyzed through careful examination of fossil records, allowing paleontologists to understand more about the diversity and evolution of theropods.
Understanding the relationship between ceratosaurs and other theropods helps in reconstructing the evolutionary pathways that led to modern birds. This clade is significant as it offers insights into the vast diversity that once existed within the group of dinosaurs that included the direct ancestors of avian species.