A few fossil traces of the Coelurosauria date back as far as the Upper Triassic. A possible, but not confirmed, example would be the archosaur
Protoavis. What has been found between then and the start of the late Jurassic is fragmentary.
Many nearly complete fossil coelurosaurians are known from the late Jurassic. Archaeopteryx is known from Solnhofen limestone at 155-150 million years ago (mya). Ornitholestes, the troodontid WDC DML 110, Coelurus fragilis and Tanycolagreus topwilsoni are all known from the Morrison Formation in Wyoming at about 150 mya.
Pedopenna are known from the
Daohugou Beds in China, whose age is still being debated, but may be about 160 Ma or 145 mya.
The wide range of fossils in the late Jurassic and morphological evidence suggests that coelurosaurian differentiation was virtually complete before the end of the Jurassic.
In the early Cretaceous, a superb range of coelurosaurian fossils (including avians) are known from the Yixian Formation in Liaoning. All known theropod dinosaurs from the Yixian Formation are coelurosaurs. Many of the coelurosaurian lineages survived to the end of the Cretaceous period (about 65 Ma) and fossils of some lineages, such as the
Tyrannosauroidea, are best known from the late Cretaceous. Most coelurosaur groups became extinct in the K/T extinction event. Only the Neornithes (modern birds) survived, and continued to diversify into the numerous forms found today.
There is consensus among paleontologists that birds are the descendants of coelurosaurs. Birds are classified by most paleontologists as belonging to the subgroup Maniraptora.