page_title: Archaeornithomimus
section_title: Description
hierarchical_section_title: Archaeornithomimus / Description
caption_attribution_description: English: A size comparison between a human male and an Archaeornithomimus asiaticus specimen.
context_page_description: Archaeornithomimus is a genus of ornithomimosaurian theropod dinosaur that lived in Asia during the Late Cretaceous period, around 96 million years ago in the Iren Dabasu Formation.
context_section_description: Archaeornithomimus was a medium sized ornithomimosaur, reaching 3.4 m (11 ft) long with a weight ranging from 45 to 91 kg (99 to 201 lb). Solid evidence coming from other ornithomimosaurian relatives suggest that Archaeornithomimus was a feathered animal, with very ratite-like feathers and equipped with a keratinous beak.
  The hindlimbs were robustly built. The third metatarsal was not pinched at the upper end, so the foot was not arctometatarsalian. The cervical vertebrae are highly pneumatized with very complex internal chambers across the neural arches and the centrum (body of the vertebra), indicating the presence of cervical air sacs. The anterior dorsal and some caudal vertebrae features some degree of pneumacity, however, the sacral vertebrae are apneumatic.
  In a 2001 study conducted by Bruce Rothschild and other paleontologists, 229 foot bones referred to Archaeornithomimus were examined for signs of stress fracture, but none were found.
caption: Size comparison with an average human male
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