Saurischian dinosaurs

Coelurosaurs

Coelurosaurs were a rather mixed group of meat-eating small, lightweight theropod dinosaurs. Representatives placed in this group lived in the three Jurassic and Cretaceous periods. Coelurosaurs are identified by having small skulls lined with sharp teeth, long necks, and arms with grasping hands. Because they were small animals only 3-4 ft in length with small bones, coelurosaur fossils are not as well preserved as the fossils of the larger dinosaurs, and many of the finds have been of just a few bone fragments.

Coelurosaurs of the Jurassic included the tiny 3ft Compsognathus: this name means 'pretty jaw', and bones were discovered in Bavaria, southern Germany. Compsognathus probably ate insects and small vertebrates.
Ornitholestes (this name means 'bird robber') was discovered at Como, Wyoming. The skull of this dinosaur suggests that it had more powerful jaws than those of Coelophysis or Compsognathus, and it may have taken larger prey. Ornitholestes also had long arms and fingers that suggest it may have been better able to grasp its prey than its relatives.

Coelurus was a coelurosaur from the late Jurassic, found in Wyoming. This species may be related to Ornitholestes.