Ornithomimus (Or-nith-oh-mime-us) belonged to a family of coelurosaur dinosaurs known as "Ostrich Mimics." Evidently, they were fast, agile runners as is the modern-day ostrich, which they resemble. Their swiftness was enhanced by light bones, long legs, and a counter-balancing tail. There were three toes on the hind foot, each ending in a blunt, triangular claw well-adapted for running.
The mouth of Ornithomimus was toothless and probably featured a horny, bird-like bill. The jaw muscles appear to have been weak. The diet, therefore, probably consisted of insects or other soft-bodied creatures, as well as eggs. The eye socket was very large, perhaps larger (in proportion to the skull) than any other dinosaur. Evidently, Ornithomimus had excellent vision and it appears that this was probably its primary sense.
The forelimb of Ornithomimus was relatively long with three fingers used for grasping. The claws on these fingers were long and curved, but not hook-like as in large meat-eating dinosaurs such as Tyrannosaurus.
Ornithomimus lived during the Late Cretaceous Period in western North America. It was approximately 14 feet long and stood 7 feet tall.