Gallimimus (pronounce /ˌɡælɨˈmaɪməs/ GAL-i-MYE-mus) , meaning 'fowl mimic', is a genus of ornithomimosaurid dinosaur from the late Cretaceous Period (Maastrichtian stage) Nemegt Formation of Mongolia. With a maximum length of 4 to 6 meters (13-20 feet) and weighing as much as 440 kilograms (970 pounds), it was one of the largest ornithomimosaurs. Gallimimus is known from multiple individuals, ranging from juvenile (about 0.5 metres tall at the hip) to adult (about 2 metres tall at the hip).