Coelurus had a small, low head like all the members of coelurid family which is about 8 in/20 cm long. Coelurus a genus of coelurosaur dinosaur from the Late Jurassic period means "hollow tail". Only one species is currently familiar, C. fragilis, described by Othniel Charles Marsh in 1879 and its displayed in the Natural History Museum, London.
Coelurus Dinosaur was a small bipedal carnivore with elongated legs and the hollow, birdlike bones (slender and considerably more elongate respect to fumur length) that characterized all early dinosaurs. The neural canal is also large in coelurus, although it is not elliptical but square.
The bone is 7.9 cm long and 1.1 cm tall, its vertebrae were long and low and thin walls to the bodies of the vertebrae.
The three best-known small theropods are Coelurus, Ornitholestes, and Tanycolagreus. Now Coelurus is possible to distinguish from Ornitholestes by various characteristics of their anatomy were Coelurus had a longer back and neck than Ornitholestes, and longer, more slender legs and feet. Coelurus and Tanycolagreus are more similar, but differ in a variety of details like shape of the upper arm, forearm, and thigh bones.
This active predator lived in forests of North America where prey was rich. Its three clawed fingers were long and strong which is designed for grasping the flesh of small animals like lizards and mammals.