The forefoot with its long slender digits is supposed to have been adapted for grasping an active and elusive prey, and the name (_Ornitho-lestes_ = bird-robber) indicates that that prey may sometimes have been the primitive birds which were its contemporaries.
In the Cretacic Period, there were also small and medium sized carnivorous dinosaurs, contemporary with the gigantic kinds; a complete skeleton of _Ornithomimus_ at the entrance to the Dinosaur Hall finely illustrates this group.

In appearance most of these small dinosaurs must have suggested long-legged bipedal lizards, running and walking on their hind limbs, with the long tail stretched out behind to balance the body.

From what we know of their tracks it seems that they walked or ran with a narrow treadway, the footsteps almost in the middle line of progress.

They did not hop like perching birds, nor did they waddle like most living reptiles.

Occasionally the tail or fore feet touched the ground as they walked; and when they sat down, they rested on the end of the pubic bones and on the tail.