Gallimimus was a bipedal dinosaur that lived during the Cretaceous Period, and is thought to have been pretty intelligent. It probably ran fast because of its body structure.
With individuals as long as 8 metres (26 ft), 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 two metres tall at the hip).
Gallimimus was rather ostrich-like, with a small head, toothless beak, large eyes, a long neck, short arms, long legs, and a long tail. A diagnostic character of Gallimimus is a distinctly short ‘hand’ relative to the humerus length, when compared to other ornithomimids. The tail was used as a counter-balance. The eyes were located on the sides of its head, meaning that it did not possess binocular vision. Like most modern birds and other theropods, it had hollow bones.
The first fossil remains of this dinosaur were discovered in early August 1963 by a team of Professor Zofia Kielan-Jaworowska at Tsagan Khushu during a Polish-Mongolian expedition to the Gobi Desert of Mongolia. The find was reported by her in 1965. In 1972, it was named and decribed by paleontologists Rinchen Barsbold, Halszka Osmólska, and Ewa Roniewicz. The only named species is the type species Gallimimus bullatus. The generic name is derived from Latin gallus, “chicken”, and mimus, “mimic”, in reference to the neural arches of the front neck vertebrae which resemble those of the Galliformes. The specific name is derived from Latin bulla, a magic capsule worn by Roman youth around the neck, in reference to a bulbous swelling in the braincase on the underside of the parasphenoid, in the form of a capsule.
Mounted skeleton cast, Natural History Museum, London