Archaeornithomimus is a genus of theropod dinosaur from the Late Cretaceous of China, 70 million years ago. Related to the more famous Gallimimus, Struthiomimus and Ornithomimus, Archaeornithomimus lived in the same manner, possibly living in flocks, eating everything from small mammals, to plants and fruit, to eggs, and even hatchlings of other Asian dinosaurs. However, they were also the potential prey for the larger Tyrannosaurids, such as Tarbosaurus.