Deinocheirus is a massive theropod, estimated in 2016 to be around 4.4 meters (14 feet) tall and 12 meters (36 feet) in length. As with most bulky animals, it had many hollow bones, some highly-pneumatized by invading air sacs, to help it save weight, though it was still a heavy animal, weighing around 6.5 - 7.3 metric tons (7.2 - 8 short tons). It is the largest ornithomimosaur ever discovered, having traded the sleek, ostrich-like body plan and speed of relatives like Ornithomimus.