Gallimimus bullatus — a birdlike runner
Gallimimus was one of the largest of a group of theropod dinosaurs known as ornithomimosaurs — the ‘bird mimicking reptiles’. Just like birds, Gallimimus had a beak with no teeth. It was most likely an omnivore, which means it ate both meat and plants — whatever it could get hold of. Today there are many animals that are omnivores, for example, bears, foxes, ostriches and even humans!
Gallimimus had flexible arms equipped with long fingers and claws. These were useful for the many different tasks of an omnivorous lifestyle, such as getting fruit, catching and holding prey, and digging dirt to find food.
Gallimimus was clearly a fast runner. Its leg proportions were similar to other fast runners, such as ostriches, horses and deer. Running fast would have been an important part of its survival, for catching prey and for fleeing predators such as Tarbosaurus, which lived at the same time and place. The popular science-fiction film Jurassic Park shows the probable predator–prey relationship of these two dinosaurs, with a flock of Gallimimus being chased by a large tyrannosaur.