Ornithomimus was a fast-running dinosaur that lived during the Late Cretaceous period, around 70 million years ago. It belonged to a group called theropods, which also includes famous dinosaurs like Tyrannosaurus rex. Ornithomimus had long legs, a lightweight body, and a long neck, making it well-suited for speed and agility. This dinosaur was likely an omnivore, feeding on plants, small animals, and possibly insects. Its beak was flat and toothless, similar to that of modern-day ostriches, which suggests it may have used it to forage for food. Fossils of Ornithomimus have been found in North America, providing valuable insights into its lifestyle and environment.