Archaeornithomimus, meaning “before bird mimic”, was a genus of dinosaur from the Late Cretaceous Period about 80 mya. It was found in China. This genus is an ancestor of the more famous Ornithomimus. Bones discovered in Maryland that were thought to be of Ornithomimus are now classified as a species of Archaeornithomimus. Some scientists believe that these bones are actually of some other small predator.
This dinosaur was probably an omnivore, eating everything from small mammals, to plants and fruit, to eggs, and even other dinosaur hatchlings. However, some scientists say there is not enough evidence to classify this dinosaur in any group or family. The type species, A. asiaticus, was described by Dale Russell in 1972. It was a dinosaur that would have been about 11 feet long, 6 feet tall, and weighed around 110 pounds. Another known species is A. affins.