In a recent study, the mass of six specimens was estimated, one-third of them weighed about 900 kg (1 short ton), the largest being UVP 015 at 957 kg (2,110 lb), suggesting specimens that big were probably more common than previously thought.[2] It stood 8–10 feet (2.4–3.0 m) tall on hind legs[7] while a large specimen would have been 11–12 feet (3.4–3.7 m) tall with a 14 foot (4.3 m) vertical arm reach, and 5–6 feet (1.5–1.8 m) high at the shoulder when walking on all fours, it was tall enough to look a man in the eye.