Dromaeosauridae
Like other theropods, dromaeosaurs were bipedal; that is, they walked on their hind legs. Other theropods walked with three toes on the ground, but fossilized footprint tracks show that most dromaeosaurs held the second toe off the ground, with only the third and fourth toes bearing the weight of the animal. The enlarged second toe had an unusually large, curved sickle-shaped claw. It is thought to have been used in capturing prey and, in the smaller species, climbing trees.