coelurosaurians

Coelurosauria, or coelurosaurians, is a major clade of theropod dinosaurs within the larger group Tetanurae. It comprises most theropods that are more closely related to birds than to Ceratosauria, and includes a broad diversity of forms from small, agile runners to large predators and herbivores. The clade originated in the Late Triassic to Early Jurassic, and its members eventually gave rise to birds, the only living coelurosaurs.

Major subgroups within Coelurosauria include Tyrannosauroidea (tyrannosaurs), Dromaeosauridae (raptors), Troodontidae, Compsognathidae, Oviraptorosauria, Therizinosauria, and Avialae (which comprises all true birds). This assemblage shows a wide range of ecologies, from light, feathered predators to beaked omnivores and large herbivores, with birds representing the living descendants.

Feather impressions and fossilized integument document extensive feather coverage among many coelurosaurs. In some lineages, such as dromaeosaurids and troodontids, feathered limbs suggest wing-like surfaces, while Avialae includes true flight. Birds are the only surviving coelurosaurs, sharing a common ancestry with non-avian coelurosaurs and retaining core skeletal features that link them to their dinosaurian heritage.